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Bibliography on: Biodiversity and Metagenomics

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ESP: PubMed Auto Bibliography 14 Nov 2022 at 01:30 Created: 

Biodiversity and Metagenomics

If evolution is the only light in which biology makes sense, and if variation is the raw material upon which selection works, then variety is not merely the spice of life, it is the essence of life — the sine qua non without which life could not exist. To understand biology, one must understand its diversity. Historically, studies of biodiversity were directed primarily at the realm of multicellular eukaryotes, since few tools existed to allow the study of non-eukaryotes. Because metagenomics allows the study of intact microbial communities, without requiring individual cultures, it provides a tool for understanding this huge, hitherto invisible pool of biodiversity, whether it occurs in free-living communities or in commensal microbiomes associated with larger organisms.

Created with PubMed® Query: biodiversity metagenomics NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2022-11-09
CmpDate: 2022-11-09

Yun Y, Su T, Gui Z, et al (2022)

Stress-responses of microbes in oil reservoir under high tetracycline exposure and their environmental risks.

Environmental pollution (Barking, Essex : 1987), 315:120355.

As the groundwater ecosystem is connected with surface, antibiotics and antibiotic resistance genes (ARGs) in aquatic environments will gradually infiltrate into the deep environment, posing a potential threat to groundwater ecosystem. However, knowledge on the environmental risk of antibiotics and ARGs in groundwater ecosystem and their ecological process still remains unexplored. In this study, lab-scale oil reservoirs under high tetracycline stress were performed to evaluate the dynamics of microbial communities, ARGs and potential functions by using 16S rRNA gene sequencing and metagenomics analysis. Although the presence of antibiotics remarkably reduced the microbial abundance and diversity in a short term, but remain stable or even increased after a long-term incubation. Antibiotic stress caused a greater diversity and abundance of ARGs, and higher numbers of ARGs-related species with the capacity to transfer ARGs to other microbes through horizontal gene transfer. Thus, a much more frequent associations of microbial community at both node- and network-level and a selective pressure on enrichment of antibiotic resistant bacteria related to "anaerobic n-alkane degradation" and "methylotrophic methanogenesis" were observed. It is important to emphasize that high antibiotic stress could also prevent some microbes related to "Sulfate reduction", "Fe(II) oxidation", "Nitrate reduction", and "Xylene and Toluene degradation". This study provides an insight into the long-term stress-responses of microbial communities and functions in oil reservoir under tetracycline exposure, which may help to elucidate the effect of antibiotic stress on biogeochemical cycling with microbial involvement in groundwater ecosystem.

RevDate: 2022-11-08
CmpDate: 2022-11-08

Yang J, Qin S, H Zhang (2022)

Precise strategies for selecting probiotic bacteria in treatment of intestinal bacterial dysfunctional diseases.

Frontiers in immunology, 13:1034727.

Abundant microbiota resides in the organs of the body, which utilize the nutrition and form a reciprocal relationship with the host. The composition of these microbiota changes under different pathological conditions, particularly in response to stress and digestive diseases, making the microbial composition and health of the hosts body interdependent. Probiotics are living microorganisms that have demonstrated beneficial effects on physical health and as such are used as supplements to ameliorate symptoms of various digestive diseases by optimizing microbial composition of the gut and restore digestive balance. However, the supplementary effect does not achieve the expected result. Therefore, a targeted screening strategy on probiotic bacteria is crucial, owing to the presence of several bacterial strains. Core bacteria work effectively in maintaining microbiological homeostasis and stabilization in the gastrointestinal tract. Some of the core bacteria can be inherited and acquired from maternal pregnancy and delivery; others can be acquired from contact with the mother, feces, and the environment. Knowing the genera and functions of the core bacteria could be vital in the isolation and selection of probiotic bacteria for supplementation. In addition, other supporting strains of probiotic bacteria are also needed. A comprehensive strategy for mining both core and supporting bacteria before its clinical use is needed. Using metagenomics or other methods of estimation to discern the typically differentiated strains of bacteria is another important strategy to treat dysbiosis. Hence, these two factors are significant to carry out targeted isolation and selection of the functional strains to compose the resulting probiotic preparation for application in both research and clinical use. In conclusion, precise probiotic supplementation, by screening abundant strains of bacteria and isolating specific probiotic strains, could rapidly establish the core microbiota needed to confer resilience, particularly in bacterial dysfunctional diseases. This approach can help identify distinct bacteria which can be used to improve supplementation therapies.

RevDate: 2022-11-08
CmpDate: 2022-11-08

Liu J, Wang J, Zhou Y, et al (2022)

Integrated omics analysis reveals differences in gut microbiota and gut-host metabolite profiles between obese and lean chickens.

Poultry science, 101(11):102165.

Abdominal fat is the major adipose tissue in chickens. In chicken, the deposition of abdominal fat affects meat yield and quality. Previous reports suggest that gut microbiota composition and function are associated with lipid metabolism. In this study, we used comparative metagenomics and metabolomics analysis to determine the gut microbiota and gut-host metabolite profiles in Shouguang (SG; a Chinese chicken breed with low-fat deposition) and Luqin (LQ; a fatty-type chicken breed with a fast growth rate) chickens. The results showed that LQ chickens had higher body weight, eviscerated yield, abdominal fat yield, abdominal fat ratio, and triglyceride (TG) content in the breast muscle than SG chickens. Untargeted metabolomics analyses showed a total of 11 liver metabolites, 19 plasma metabolites, and 30 cecal metabolites differentially enriched in LQ and SG chickens based on variable importance in the projection (VIP) ≥ 1 and P ≤ 0.05. These metabolites are involved in lipid and amino acid metabolism. The relative abundance of bacteria in the microbiota differed significantly between the 2 chicken breeds. The functional prediction of microbiota abundant in LQ chickens was starch and lactose degradation. Erysipelatoclostridium was abundant in LQ chickens and significantly positively correlated to palmitoyl ethanolamide (PEA), a key regulator of lipid metabolism. Our findings revealed differences in liver and plasma metabolites between chicken breeds with different adipose deposition capacities. Long-chain acylcarnitines might be important markers of adipose deposition differences in chickens. The cecum's microbial communities and metabolome profiles significantly differed between LQ and SG chickens. However, the relationship between cecal microbiota and their metabolites and liver and plasma metabolites is not thoroughly understood. Future research will focus on relating tissue metabolite changes to intestinal microbiota and their effects on body fat deposition.

RevDate: 2022-11-08
CmpDate: 2022-11-08

Corander J, Hanage WP, J Pensar (2022)

Causal discovery for the microbiome.

The Lancet. Microbe, 3(11):e881-e887.

Measurement and manipulation of the microbiome is generally considered to have great potential for understanding the causes of complex diseases in humans, developing new therapies, and finding preventive measures. Many studies have found significant associations between the microbiome and various diseases; however, Koch's classical postulates remind us about the importance of causative reasoning when considering the relationship between microbes and a disease manifestation. Although causal discovery in observational microbiome data faces many challenges, methodological advances in causal structure learning have improved the potential of data-driven prediction of causal effects in large-scale biological systems. In this Personal View, we show the capability of existing methods for inferring causal effects from metagenomic data, and we highlight ways in which the introduction of causal structures that are more flexible than existing structures offers new opportunities for causal reasoning. Our observations suggest that microbiome research can further benefit from tools developed in the past 5 years in causal discovery and learn from their applications elsewhere.

RevDate: 2022-11-08
CmpDate: 2022-11-08

Li Y, Yu Y, Wu X, et al (2022)

Specially designed yogurt supplemented with combination of pro- and prebiotics relieved constipation in mice and humans.

Nutrition (Burbank, Los Angeles County, Calif.), 103-104:111802.

OBJECTIVE: Functional constipation is a gastrointestinal disorder that affects millions of people and is correlated with gut microbiome dysbiosis. The currently available treatments are ineffective; therefore, novel treatment schemes targeting the gut microbiome are desired. The aim of this study was to assess the effects of yogurt supplemented with seven probiotic strains and six types of dietary fibers on functional constipation.

METHODS: In the mouse study, mice with induced constipation were administered the yogurt once a day for 1 wk, with fecal parameters and intestinal transit rate measured. In the clinical study, participants with constipation (N = 86) were given the yogurt once daily (200 g) for 4 wk. Fecal and blood samples along with Patient Assessment of Constipation-symptoms and Patient Assessment of Constipation-Quality of Life Scale questionnaires were collected to evaluate the safety and efficacy of the yogurt. Shotgun metagenomic sequencing was performed to analyze fecal samples of both mice and humans.

RESULTS: We found that constipated mice had different gut microbiomes compared with those in healthy controls; yogurt treatment significantly relieved constipation-related symptoms and resulted in shifts in the microbiome. Yogurt also relieved symptoms of antibiotic-induced constipation in mice and restored the gut microbiome to a certain extent. In the clinical trial with 86 patients, yogurt administration significantly improved constipation symptoms and showed no serious adverse effects (was generally considered safe). However, subsequent metagenomic profiling of the gut microbiome did not reveal significant changes in the microbial composition, in contrast to the results in mice. We hypothesize that the differences in dosage between mice and humans may attribute to such discrepancies, and microbiome changes may not be necessary for improvements of constipation symptoms in humans.

CONCLUSION: Results from this study showed that yogurt can potentially be used for the treatment of constipation.

RevDate: 2022-11-08
CmpDate: 2022-11-08

Nandi SK, Basu S, Bhattacharjya A, et al (2022)

Interplay of gut microbiome, fatty acids, and the endocannabinoid system in regulating development, progression, immunomodulation, and chemoresistance of cancer.

Nutrition (Burbank, Los Angeles County, Calif.), 103-104:111787.

The roles of gut microorganisms in cancer are diverse. Studies on metagenomics and bioinformatics have documented diverse microbial etiology in different tumors. Evidence supports that a commensal microbiome could provide a promising strategy to treat and prevent cancer through interference in several biologic processes, such as host cell survival and death, host immune function, inflammation, oncogenic signaling, and several hormone receptor signaling and detoxification pathways. The cumulative evidence recommends that metabolites of commensal gut microorganisms (e.g., short-chain fatty acids, omega-3 and -6 fatty acids) play an important role in cancer prevention, with a robust antiproliferative effect of omega-3 fatty acids. Intriguingly, the endocannabinoid system (omega-3 and -6 fatty acid-derived neurotransmitter of the body) shows diverse effects on cancer prevention and oncogenesis depending on the context of the tumor microenvironment. Thus, an interplay of gut microorganisms with their fatty acid metabolites and the endocannabinoid system play an important role in the development, progression, immunomodulation, and chemoresistance of cancer. In this review, we highlight aspects of the current knowledge of and interactions between the microbiome with fatty acids and the host endocannabinoid system. We also document their effect on host immunomodulation and chemoresistance, and discuss how these insights might translate into future development of microbiome-targeted therapeutic interventions.

RevDate: 2022-11-05

Sieber G, Beisser D, Rothenberger JL, et al (2022)

Microbial community shifts induced by plastic and zinc as substitutes of tire abrasion.

Scientific reports, 12(1):18684.

Aquatic environments serve as a sink for anthropogenic discharges. A significant part of the discharge is tire wear, which is increasingly being released into the environment, causing environmental disasters due to their longevity and the large number of pollutants they contain. Main components of tires are plastic and zinc, which therefore can be used as substitutes for tire abrasion to study the effect on microbial life. We investigate environmentally realistic concentrations of plastic and zinc on a freshwater microeukaryotic community using high-throughput sequencing of the 18S V9 region over a 14-day exposure period. Apart from a generally unchanged diversity upon exposure to zinc and nanoplastics, a change in community structure due to zinc is evident, but not due to nanoplastics. Evidently, nanoplastic particles hardly affect the community, but zinc exposure results in drastic functional abundance shifts concerning the trophic mode. Phototrophic microorganisms were almost completely diminished initially, but photosynthesis recovered. However, the dominant taxa performing photosynthesis changed from bacillariophytes to chlorophytes. While phototrophic organisms are decreasing in the presence of zinc, the mixotrophic fraction initially benefitted and the heterotrophic fraction were benefitting throughout the exposure period. In contrast to lasting changes in taxon composition, the functional community composition is initially strongly imbalanced after application of zinc but returns to the original state.

RevDate: 2022-11-03

Yi X, Wen P, Liang JL, et al (2022)

Phytostabilization mitigates antibiotic resistance gene enrichment in a copper mine tailings pond.

Journal of hazardous materials, 443(Pt B):130255 pii:S0304-3894(22)02049-0 [Epub ahead of print].

Mining-impacted environments are distributed globally and have become increasingly recognized as hotspots of antibiotic resistance genes (ARGs). However, there are currently no reports on treatment technologies to deal with such an important environmental problem. To narrow this knowledge gap, we implemented a phytostabilization project in an acidic copper mine tailings pond and employed metagenomics to explore ARG characteristics in the soil samples. Our results showed that phytostabilization decreased the total ARG abundance in 0-10 cm soil layer by 75 %, which was companied by a significant decrease in ARG mobility, and a significant increase in ARG diversity and microbial diversity. Phytostabilization was also found to drastically alter the ARG host composition and to significantly reduce the total abundance of virulence factor genes of ARG hosts. Soil nutrient status, heavy metal toxicity and SO42- concentration were important physicochemical factors to affect the total ARG abundance, while causal mediation analysis showed that their effects were largely mediated by the changes in ARG mobility and microbial diversity. The increase in ARG diversity associated with phytostabilization was mainly mediated by a small subgroup of ARG hosts, most of which could not be classified at the genus level and deserve further research in the future.

RevDate: 2022-11-03
CmpDate: 2022-11-03

Karakan T, Gundogdu A, Alagözlü H, et al (2022)

Artificial intelligence-based personalized diet: A pilot clinical study for irritable bowel syndrome.

Gut microbes, 14(1):2138672.

We enrolled consecutive IBS-M patients (n = 25) according to Rome IV criteria. Fecal samples were obtained from all patients twice (pre-and post-intervention) and high-throughput 16S rRNA sequencing was performed. Six weeks of personalized nutrition diet (n = 14) for group 1 and a standard IBS diet (n = 11) for group 2 were followed. AI-based diet was designed based on optimizing a personalized nutritional strategy by an algorithm regarding individual gut microbiome features. The IBS-SSS evaluation for pre- and post-intervention exhibited significant improvement (p < .02 and p < .001 for the standard IBS diet and personalized nutrition groups, respectively). While the IBS-SSS evaluation changed to moderate from severe in 78% (11 out of 14) of the personalized nutrition group, no such change was observed in the standard IBS diet group. A statistically significant increase in the Faecalibacterium genus was observed in the personalized nutrition group (p = .04). Bacteroides and putatively probiotic genus Propionibacterium were increased in the personalized nutrition group. The change (delta) values in IBS-SSS scores (before-after) in personalized nutrition and standard IBS diet groups are significantly higher in the personalized nutrition group. AI-based personalized microbiome modulation through diet significantly improves IBS-related symptoms in patients with IBS-M. Further large-scale, randomized placebo-controlled trials with long-term follow-up (durability) are needed.

RevDate: 2022-11-02
CmpDate: 2022-11-02

Alessandri G, Fontana F, Mancabelli L, et al (2022)

Exploring species-level infant gut bacterial biodiversity by meta-analysis and formulation of an optimized cultivation medium.

NPJ biofilms and microbiomes, 8(1):88.

In vitro gut cultivation models provide host-uncoupled, fast, and cost-efficient solutions to investigate the effects of intrinsic and extrinsic factors impacting on both composition and functionality of the intestinal microbial ecosystem. However, to ensure the maintenance and survival of gut microbial players and preserve their functions, these systems require close monitoring of several variables, including oxygen concentration, pH, and temperature, as well as the use of a culture medium satisfying the microbial nutritional requirements. In this context, in order to identify the macro- and micro-nutrients necessary for in vitro cultivation of the infant gut microbiota, a meta-analysis based on 1669 publicly available shotgun metagenomic samples corresponding to fecal samples of healthy, full-term infants aged from a few days to three years was performed to define the predominant species characterizing the "infant-like" gut microbial ecosystem. A subsequent comparison of growth performances was made using infant fecal samples that contained the most abundant bacterial taxa of the infant gut microbiota, when cultivated on 18 different culture media. This growth analysis was performed by means of flow cytometry-based bacterial cell enumeration and shallow shotgun sequencing, which allowed the formulation of an optimized growth medium, i.e., Infant Gut Super Medium (IGSM), which maintains and sustains the infant gut microbial biodiversity under in vitro growth conditions. Furthermore, this formulation was used to evaluate the in vitro effect of two drugs commonly used in pediatrics, i.e., acetaminophen and simethicone, on the taxonomic composition of the infant gut microbiota.

RevDate: 2022-11-02
CmpDate: 2022-11-02

Chen J, X Zhang (2022)

dICC: distance-based intraclass correlation coefficient for metagenomic reproducibility studies.

Bioinformatics (Oxford, England), 38(21):4969-4971.

SUMMARY: Due to the sparsity and high dimensionality, microbiome data are routinely summarized into pairwise distances capturing the compositional differences. Many biological insights can be gained by analyzing the distance matrix in relation to some covariates. A microbiome sampling method that characterizes the inter-sample relationship more reproducibly is expected to yield higher statistical power. Traditionally, the intraclass correlation coefficient (ICC) has been used to quantify the degree of reproducibility for a univariate measurement using technical replicates. In this work, we extend the traditional ICC to distance measures and propose a distance-based ICC (dICC). We derive the asymptotic distribution of the sample-based dICC to facilitate statistical inference. We illustrate dICC using a real dataset from a metagenomic reproducibility study.

dICC is implemented in the R CRAN package GUniFrac.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RevDate: 2022-11-01
CmpDate: 2022-11-01

Thakor A, Cheng J, TC Charles (2023)

Isolation of Genes Encoding Carbon Metabolism Pathways from Complex Microbial Communities.

Methods in molecular biology (Clifton, N.J.), 2555:115-123.

The ability to produce high-value products using bacteria will increasingly rely on continued research to make large-scale bacterial fermentation cost-efficient. Engineering bacteria to use alternate carbon sources as feedstock provides an opportunity to reduce production costs. Using inexpensive carbon sources from various forms of waste provides an opportunity to substantially reduce feedstock costs. Functional carbon metabolism pathways can be identified by the introduction of metagenomic libraries into the organism of interest followed by screening for the desired phenotype. We present here a method to transfer metagenomic libraries from E. coli to Pseudomonas alloputida, followed by screening for use of galactose as a sole carbon source.

RevDate: 2022-11-01
CmpDate: 2022-11-01

Hollensteiner J, Wemheuer F, Schneider D, et al (2023)

Extraction of Total DNA and RNA from Marine Filter Samples and Generation of a Universal cDNA as Universal Template for Marker Gene Studies.

Methods in molecular biology (Clifton, N.J.), 2555:13-21.

Microbial communities play an important role in marine ecosystem processes. Although the number of studies targeting marker genes such as the 16S rRNA gene has increased during the last years, the vast majority of marine diversity are rather unexplored. Moreover, most studies focused on the entire microbial community and thus do not assess the active fraction of the microbial community. Here, we describe a detailed protocol for the simultaneous extraction of DNA and RNA from marine water samples and the generation of cDNA from the isolated RNA that can be used as a universal template in various marker gene studies.

RevDate: 2022-11-01
CmpDate: 2022-11-01

Simon C, R Daniel (2023)

Construction of Small-Insert and Large-Insert Metagenomic Libraries.

Methods in molecular biology (Clifton, N.J.), 2555:1-12.

The vast majority of the Earth's biological diversity are hidden in uncultured and yet uncharacterized microbial genomes. The construction of metagenomic libraries is one cultivation-independent molecular approach to assess this unexplored genetic reservoir. High numbers of novel biocatalysts have been identified by function-based or sequence-based screening of metagenomic libraries derived from various environments. Here, we describe detailed protocols for the construction of metagenomic small-insert and large-insert libraries in plasmids and fosmids, respectively, from environmental DNA.

RevDate: 2022-10-31
CmpDate: 2022-10-31

Ju Y, Wang X, Wang Y, et al (2022)

[Application of metagenomic and culturomic technologies in fecal microbiota transplantation: a review].

Sheng wu gong cheng xue bao = Chinese journal of biotechnology, 38(10):3594-3605.

Fecal microbiota transplantation (FMT) refers to using the intestinal microorganisms present in the feces or processed feces from healthy people for treating various types of diseases, such as digestive and metabolic diseases. The rapid development of metagenomic and culturomic technologies in gut microbiome analysis provides powerful tools for the FMT research and its clinical applications. Metagenomics technologies comprehensively revealed the diversity and functions of gut microbiota under health and disease conditions, while culturomics technologies helped isolation and identification of "unculturable" bacteria in the human gut under conventional culture conditions. The combination of these two technologies not only enabled us better understand the FMT regularities of cause and effect in clinical practices, but also effectively promoted its applications. Considering the above advantages, this article summarized the applications of metagenomics and culturomics technologies in FMT and prospected its future development trend.

RevDate: 2022-10-31
CmpDate: 2022-10-31

Aalam SMM, Crasta DN, Roy P, et al (2022)

Genesis of fecal floatation is causally linked to gut microbial colonization in mice.

Scientific reports, 12(1):18109.

The origin of fecal floatation phenomenon remains poorly understood. Following our serendipitous discovery of differences in buoyancy of feces from germ-free and conventional mice, we characterized microbial and physical properties of feces from germ-free and gut-colonized (conventional and conventionalized) mice. The gut-colonization associated differences were assessed in feces using DNA, bacterial-PCR, scanning electron microscopy, FACS, thermogravimetry and pycnometry. Based on the differences in buoyancy of feces, we developed levô in fimo test (LIFT) to distinguish sinking feces (sinkers) of germ-free mice from floating feces (floaters) of gut-colonized mice. By simultaneous tracking of microbiota densities and gut colonization kinetics in fecal transplanted mice, we provide first direct evidence of causal relationship between gut microbial colonization and fecal floatation. Rare discordance in LIFT and microbiota density indicated that enrichment of gasogenic gut colonizers may be necessary for fecal floatation. Finally, fecal metagenomics analysis of 'floaters' from conventional and syngeneic fecal transplanted mice identified colonization of > 10 gasogenic bacterial species including highly prevalent B. ovatus, an anaerobic commensal bacteria linked with flatulence and intestinal bowel diseases. The findings reported here will improve our understanding of food microbial biotransformation and gut microbial regulators of fecal floatation in human health and disease.

RevDate: 2022-10-28

Jameson E, Taubert M, Angel R, et al (2023)

DNA-, RNA-, and Protein-Based Stable-Isotope Probing for High-Throughput Biomarker Analysis of Active Microorganisms.

Methods in molecular biology (Clifton, N.J.), 2555:261-282.

Stable-isotope probing (SIP) enables researchers to target active populations within complex microbial communities, which is achieved by providing growth substrates enriched in heavy isotopes, usually in the form of 13C, 18O, or 15N. After growth on the substrate and subsequent extraction of microbial biomarkers, typically nucleic acids or proteins, the SIP technique is used for the recovery and analysis of isotope-labelled biomarkers from active microbial populations. In the years following the initial development of DNA- and RNA-based SIP, it was common practice to characterize labelled populations by targeted gene analysis. Such approaches usually involved fingerprint-based analyses or sequencing clone libraries containing 16S rRNA genes or functional marker gene amplicons. Although molecular fingerprinting remains a valuable approach for rapid confirmation of isotope labelling, recent advances in sequencing technology mean that it is possible to obtain affordable and comprehensive amplicon profiles, or even metagenomes and metatranscriptomes from SIP experiments. Not only can the abundance of microbial groups be inferred from metagenomes, but researchers can bin, assemble, and explore individual genomes to build hypotheses about the metabolic capabilities of labelled microorganisms. Analysis of labelled mRNA is a more recent advance that can provide independent metatranscriptome-based analysis of active microorganisms. The power of metatranscriptomics is that mRNA abundance often correlates closely with the corresponding activity of encoded enzymes, thus providing insight into microbial metabolism at the time of sampling. Together, these advances have improved the sensitivity of SIP methods and allowed using labelled substrates at environmentally relevant concentrations. Particularly as methods improve and costs continue to drop, we expect that the integration of SIP with multiple omics-based methods will become prevalent components of microbial ecology studies, leading to further breakthroughs in our understanding of novel microbial populations and elucidation of the metabolic function of complex microbial communities. In this chapter, we provide protocols for obtaining labelled DNA, RNA, and proteins that can be used for downstream omics-based analyses.

RevDate: 2022-10-28

Weiland-Bräuer N, Saleh L, RA Schmitz (2023)

Functional Metagenomics as a Tool to Tap into Natural Diversity of Valuable Biotechnological Compounds.

Methods in molecular biology (Clifton, N.J.), 2555:23-49.

The marine ecosystem covers more than 70% of the world's surface, and oceans represent a source of varied types of organisms due to the diversified environment. Consequently, the marine environment is an exceptional depot of novel bioactive natural products, with structural and chemical features generally not found in terrestrial habitats. Here, in particular, microbes represent a vast source of unknown and probably new physiological characteristics. They have evolved during extended evolutionary processes of physiological adaptations under various environmental conditions and selection pressures. However, to date, the biodiversity of marine microbes and the versatility of their bioactive compounds and metabolites have not been fully explored. Thus, metagenomic tools are required to exploit the untapped marine microbial diversity and their bioactive compounds. This chapter focuses on function-based marine metagenomics to screen for bioactive molecules of value for biotechnology. Functional metagenomic strategies are described, including sampling in the marine environment, constructing marine metagenomic large-insert libraries, and examples on function-based screens for quorum quenching and anti-biofilm activities.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Gao Y, Sohn MB, J Wang (2022)

Editorial: Gut virome and human health.

Frontiers in cellular and infection microbiology, 12:1043256.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Rey-Mariño A, MP Francino (2022)

Nutrition, Gut Microbiota, and Allergy Development in Infants.

Nutrients, 14(20): pii:nu14204316.

The process of gut microbiota development in infants is currently being challenged by numerous factors associated with the contemporary lifestyle, including diet. A thorough understanding of all aspects of microbiota development will be necessary for engineering strategies that can modulate it in a beneficial direction. The long-term consequences for human development and health of alterations in the succession pattern that forms the gut microbiota are just beginning to be explored and require much further investigation. Nevertheless, it is clear that gut microbiota development in infancy bears strong associations with the risk for allergic disease. A useful understanding of microbial succession in the gut of infants needs to reveal not only changes in taxonomic composition but also the development of functional capacities through time and how these are related to diet and various environmental factors. Metagenomic and metatranscriptomic studies have started to produce insights into the trends of functional repertoire and gene expression change within the first year after birth. This understanding is critical as during this period the most substantial development of the gut microbiota takes place and the relations between gut microbes and host immunity are established. However, further research needs to focus on the impact of diet on these changes and on how diet can be used to counteract the challenges posed by modern lifestyles to microbiota development and reduce the risk of allergic disease.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Malicka M, Magurno F, Z Piotrowska-Seget (2022)

Phenol and Polyaromatic Hydrocarbons Are Stronger Drivers Than Host Plant Species in Shaping the Arbuscular Mycorrhizal Fungal Component of the Mycorrhizosphere.

International journal of molecular sciences, 23(20): pii:ijms232012585.

Changes in soil microbial communities in response to hydrocarbon pollution are critical indicators of disturbed ecosystem conditions. A core component of these communities that is functionally adjusted to the life-history traits of the host and environmental factors consists of arbuscular mycorrhizal fungi (AMF). AMF communities associated with Poa trivialis and Phragmites australis growing at a phenol and polynuclear aromatic hydrocarbon (PAH)-contaminated site and at an uncontaminated site were compared based on LSU rDNA sequencing. Dissimilarities in species composition and community structures indicated soil pollution as the main factor negatively affecting the AMF diversity. The AMF communities at the contaminated site were dominated by fungal generalists (Rhizophagus, Funneliformis, Claroideoglomus, Paraglomus) with wide ecological tolerance. At the control site, the AMF communities were characterized by higher taxonomic and functional diversity than those exposed to the contamination. The host plant identity was the main driver distinguishing the two AMF metacommunities. The AMF communities at the uncontaminated site were represented by Polonospora, Paraglomus, Oehlia, Nanoglomus, Rhizoglomus, Dominikia, and Microdominikia. Polonosporaceae and Paraglomeraceae were particularly dominant in the Ph. australis mycorrhizosphere. The high abundance of early diverging AMF could be due to the use of primers able to detect lineages such as Paraglomeracae that have not been recognized by previously used 18S rDNA primers.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Escuder-Rodríguez JJ, DeCastro ME, Saavedra-Bouza A, et al (2022)

Insights on Microbial Communities Inhabiting Non-Volcanic Hot Springs.

International journal of molecular sciences, 23(20): pii:ijms232012241.

The northwest of Spain has an abundance of non-volcanic hot springs that, until recently, had only been used for thermalism activities. One of such hot springs, Muiño da Veiga, has now been explored using metagenomics to study the microbial community that inhabits these high-temperature circumneutral continental waters. Sequencing of the metagenome allowed the characterization of its composition, diversity, metabolic connections and potential as a source for thermozymes, as well as its ability to assemble MAGs. A diverse microbial community dominated by Bacteria domain members was revealed, particularly from the early-branching Aquificales group. The most abundant genus was Sulfurihydrogenibium, known for its implication in sulfur cycling and for forming mats that enable novel niches. The variety of primary producers with autotrophic pathways (and specifically the sulfur oxidizing pathway) expands the range of available nutrients, and the increase in biomass forms thicker mats, resulting in more available niches and broader microbial diversity. Nonetheless, certain metabolic pathways were attributed to less abundant members of the microbial community, reinforcing the idea that the rare biosphere plays important roles in the network of interactions present in an ecosystem and acts as genetic reservoirs. In addition, three of the assembled MAGs represent novel microbial diversity found in this hot spring. Moreover, the presence of enzymes and microorganisms with possible biotechnological applications was confirmed, including proteases, lipases and cell-wall degrading enzymes, pointing to the potential for the hot spring as a source for thermozymes.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Vanstokstraeten R, Mackens S, Callewaert E, et al (2022)

Culturomics to Investigate the Endometrial Microbiome: Proof-of-Concept.

International journal of molecular sciences, 23(20): pii:ijms232012212.

The microbiome of the reproductive tract has been associated with (sub)fertility and it has been suggested that dysbiosis reduces success rates and pregnancy outcomes. The endometrial microbiome is of particular interest given the potential impact on the embryo implantation. To date, all endometrial microbiome studies have applied a metagenomics approach. A sequencing-based technique, however, has its limitations, more specifically in adequately exploring low-biomass settings, such as intra-uterine/endometrial samples. In this proof-of-concept study, we demonstrate the applicability of culturomics, a high-throughput culturing approach, to investigate the endometrial microbiome. Ten subfertile women undergoing diagnostic hysteroscopy and endometrial biopsy, as part of their routine work-up at Brussels IVF, were included after their informed consent. Biopsies were used to culture microbiota for up to 30 days in multiple aerobic and anaerobic conditions. Subsequent WASPLab®-assisted culturomics enabled a standardized methodology. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) or 16S rRNA sequencing was applied to identify all of bacterial and fungal isolates. Eighty-three bacterial and two fungal species were identified. The detected species were in concordance with previously published metagenomics-based endometrial microbiota analyses as 77 (91%) of them belonged to previously described genera. Nevertheless, highlighting the added value of culturomics to identify most isolates at the species level, 53 (62.4%) of the identified species were described in the endometrial microbiota for the first time. This study shows the applicability and added value of WASPLab®-assisted culturomics to investigate the low biomass endometrial microbiome at a species level.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Bhattacharya C, Tierney BT, Ryon KA, et al (2022)

Supervised Machine Learning Enables Geospatial Microbial Provenance.

Genes, 13(10): pii:genes13101914.

The recent increase in publicly available metagenomic datasets with geospatial metadata has made it possible to determine location-specific, microbial fingerprints from around the world. Such fingerprints can be useful for comparing microbial niches for environmental research, as well as for applications within forensic science and public health. To determine the regional specificity for environmental metagenomes, we examined 4305 shotgun-sequenced samples from the MetaSUB Consortium dataset-the most extensive public collection of urban microbiomes, spanning 60 different cities, 30 countries, and 6 continents. We were able to identify city-specific microbial fingerprints using supervised machine learning (SML) on the taxonomic classifications, and we also compared the performance of ten SML classifiers. We then further evaluated the five algorithms with the highest accuracy, with the city and continental accuracy ranging from 85-89% to 90-94%, respectively. Thereafter, we used these results to develop Cassandra, a random-forest-based classifier that identifies bioindicator species to aid in fingerprinting and can infer higher-order microbial interactions at each site. We further tested the Cassandra algorithm on the Tara Oceans dataset, the largest collection of marine-based microbial genomes, where it classified the oceanic sample locations with 83% accuracy. These results and code show the utility of SML methods and Cassandra to identify bioindicator species across both oceanic and urban environments, which can help guide ongoing efforts in biotracing, environmental monitoring, and microbial forensics (MF).

RevDate: 2022-10-28
CmpDate: 2022-10-28

Li M, Tyx RE, Rivera AJ, et al (2022)

What Can We Learn about the Bias of Microbiome Studies from Analyzing Data from Mock Communities?.

Genes, 13(10): pii:genes13101758.

It is known that data from both 16S and shotgun metagenomics studies are subject to biases that cause the observed relative abundances of taxa to differ from their true values. Model community analyses, in which the relative abundances of all taxa in the sample are known by construction, seem to offer the hope that these biases can be measured. However, it is unclear whether the bias we measure in a mock community analysis is the same as we measure in a sample in which taxa are spiked in at known relative abundance, or if the biases we measure in spike-in samples is the same as the bias we would measure in a real (e.g., biological) sample. Here, we consider these questions in the context of 16S rRNA measurements on three sets of samples: the commercially available Zymo cells model community; the Zymo model community mixed with Swedish Snus, a smokeless tobacco product that is virtually bacteria-free; and a set of commercially available smokeless tobacco products. Each set of samples was subject to four different extraction protocols. The goal of our analysis is to determine whether the patterns of bias observed in each set of samples are the same, i.e., can we learn about the bias in the commercially available smokeless tobacco products by studying the Zymo cells model community?

RevDate: 2022-10-28
CmpDate: 2022-10-28

Miao Q, Zhang X, Wang Y, et al (2022)

Characterization of Novel Pectinolytic Enzymes Derived from the Efficient Lignocellulose Degradation Microbiota.

Biomolecules, 12(10): pii:biom12101388.

Diverse pectinolytic enzymes are widely applied in the food, papermaking, and other industries, and they account for more than 25% of the global industrial enzyme demands. Efficient lignocellulose degradation microbiota are reservoirs of pectinolytic enzymes and other lignocellulose-degrading genes. Metagenomics has been widely used to discover new pectinolytic enzymes. Here, we used a metagenomic strategy to characterize pectinolytic genes from one efficient lignocellulose-degrading microbiota derived from pulp and paper wastewater treatment microbiota. A total of 23 predicted full-length GH28 and PL1 family pectinolytic genes were selectively cloned and expressed in Escherichia coli, and 5 of the expressed proteins had pectinolytic activities. Among them, the characterization of one pectinolytic enzyme, PW-pGH28-3, which has a 58.4% identity with an exo-polygalacturonase gene of Aquipluma nitroreducens, was further investigated. The optimal pH and optimal temperature of PW-pGH28-3 were 8.0 and 40 °C, respectively, and its pectinolytic activity at the optimal condition was 13.5 ± 1.1 U/mg protein. Bioinformatics analyses and structural modeling suggest that PW-pGH28-3 is a novel secretory exo-polygalacturonase, which is confirmed by its hydrolysates of polygalacturonic acid. The detection of PW-pGH28-3 and other pectinolytic genes showed that efficient lignocellulose degradation microbiota could provide potential efficient pectinolytic enzymes for industrial application. In the future, improving metagenomic screening efficiency would discover efficient lignocellulose-degrading enzymes and lead to the sustainable and green utilization of lignocellulose.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Mishra AK, Sudalaimuthuasari N, Hazzouri KM, et al (2022)

Tapping into Plant-Microbiome Interactions through the Lens of Multi-Omics Techniques.

Cells, 11(20): pii:cells11203254.

This review highlights the pivotal role of root exudates in the rhizosphere, especially the interactions between plants and microbes and between plants and plants. Root exudates determine soil nutrient mobilization, plant nutritional status, and the communication of plant roots with microbes. Root exudates contain diverse specialized signaling metabolites (primary and secondary). The spatial behavior of these metabolites around the root zone strongly influences rhizosphere microorganisms through an intimate compatible interaction, thereby regulating complex biological and ecological mechanisms. In this context, we reviewed the current understanding of the biological phenomenon of allelopathy, which is mediated by phytotoxic compounds (called allelochemicals) released by plants into the soil that affect the growth, survival, development, ecological infestation, and intensification of other plant species and microbes in natural communities or agricultural systems. Advances in next-generation sequencing (NGS), such as metagenomics and metatranscriptomics, have opened the possibility of better understanding the effects of secreted metabolites on the composition and activity of root-associated microbial communities. Nevertheless, understanding the role of secretory metabolites in microbiome manipulation can assist in designing next-generation microbial inoculants for targeted disease mitigation and improved plant growth using the synthetic microbial communities (SynComs) tool. Besides a discussion on different approaches, we highlighted the advantages of conjugation of metabolomic approaches with genetic design (metabolite-based genome-wide association studies) in dissecting metabolome diversity and understanding the genetic components of metabolite accumulation. Recent advances in the field of metabolomics have expedited comprehensive and rapid profiling and discovery of novel bioactive compounds in root exudates. In this context, we discussed the expanding array of metabolomics platforms for metabolome profiling and their integration with multivariate data analysis, which is crucial to explore the biosynthesis pathway, as well as the regulation of associated pathways at the gene, transcript, and protein levels, and finally their role in determining and shaping the rhizomicrobiome.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Kim CY, Ma J, I Lee (2022)

HiFi metagenomic sequencing enables assembly of accurate and complete genomes from human gut microbiota.

Nature communications, 13(1):6367.

Advances in metagenomic assembly have led to the discovery of genomes belonging to uncultured microorganisms. Metagenome-assembled genomes (MAGs) often suffer from fragmentation and chimerism. Recently, 20 complete MAGs (cMAGs) have been assembled from Oxford Nanopore long-read sequencing of 13 human fecal samples, but with low nucleotide accuracy. Here, we report 102 cMAGs obtained by Pacific Biosciences (PacBio) high-accuracy long-read (HiFi) metagenomic sequencing of five human fecal samples, whose initial circular contigs were selected for complete prokaryotic genomes using our bioinformatics workflow. Nucleotide accuracy of the final cMAGs was as high as that of Illumina sequencing. The cMAGs could exceed 6 Mbp and included complete genomes of diverse taxa, including entirely uncultured RF39 and TANB77 orders. Moreover, cMAGs revealed that regions hard to assemble by short-read sequencing comprised mostly genomic islands and rRNAs. HiFi metagenomic sequencing will facilitate cataloging accurate and complete genomes from complex microbial communities, including uncultured species.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Nzabarushimana E, H Tang (2022)

Functional profile of host microbiome indicates Clostridioides difficile infection.

Gut microbes, 14(1):2135963.

Clostridioides difficile infection (CDI) is a gastro-intestinal (GI) infection that illustrates how perturbations in symbiotic host-microbiome interactions render the GI tract vulnerable to the opportunistic pathogens. CDI also serves as an example of how such perturbations could be reversed via gut microbiota modulation mechanisms, especially fecal microbiota transplantation (FMT). However, microbiome-mediated diagnosis of CDI remains understudied. Here, we evaluated the diagnostic capabilities of the fecal microbiome on the prediction of CDI. We used the metagenomic sequencing data from ten previous studies, encompassing those acquired from CDI patients treated by FMT, CDI-negative patients presenting other intestinal health conditions, and healthy volunteers taking antibiotics. We designed a hybrid species/function profiling approach that determines the abundances of microbial species in the community contributing to its functional profile. These functionally informed taxonomic profiles were then used for classification of the microbial samples. We used logistic regression (LR) models using these features, which showed high prediction accuracy (with an average AUC≥0.91), substantiating that the species/function composition of the gut microbiome has a robust diagnostic prediction of CDI. We further assessed the confounding impact of antibiotic therapy on CDI prediction and found that it is distinguishable from the CDI impact. Finally, we devised a log-odds score computed from the output of the LR models to quantify the likelihood of CDI in a gut microbiome sample and applied it to evaluating the effectiveness of FMT based on post-FMT microbiome samples. The results showed that the gut microbiome of patients exhibited a gradual but steady improvement after receiving successful FMT, indicating the restoration of the normal microbiome functions.

RevDate: 2022-10-29
CmpDate: 2022-10-28

Fransson E, Gudnadottir U, Hugerth LW, et al (2022)

Cohort profile: the Swedish Maternal Microbiome project (SweMaMi) - assessing the dynamic associations between the microbiome and maternal and neonatal adverse events.

BMJ open, 12(10):e065825.

PURPOSE: The Swedish Maternal Microbiome (SweMaMi) project was initiated to better understand the dynamics of the microbiome in pregnancy, with longitudinal microbiome sampling, shotgun metagenomics, extensive questionnaires and health registry linkage.

PARTICIPANTS: Pregnant women were recruited before the 20th gestational week during 2017-2021 in Sweden. In total, 5439 pregnancies (5193 unique women) were included. For 3973 pregnancies (73%), samples were provided at baseline, and for 3141 (58%) at all three timepoints (second and third trimester and postpartum). In total, 38 591 maternal microbiome samples (vaginal, faecal and saliva) and 3109 infant faecal samples were collected. Questionnaires were used to collect information on general, reproductive and mental health, diet and lifestyle, complemented by linkage to the nationwide health registries, also used to follow up the health of the offspring (up to age 10).

FINDINGS TO DATE: The cohort is fairly representative for the total Swedish pregnant population (data from 2019), with 41% first-time mothers. Women with university level education, born in Sweden, with normal body mass index, not using tobacco-products and aged 30-34 years were slightly over-represented.

FUTURE PLANS: The sample and data collection were finalised in November 2021. The next steps are the characterisation of the microbial DNA and linkage to the health and demographic information from the questionnaires and registries. The role of the microbiome on maternal and neonatal outcomes and early-childhood diseases will be explored (including preterm birth, miscarriage) and the role and interaction of other risk factors and confounders (including endometriosis, polycystic ovarian syndrome, diet, drug use). This is currently among the largest pregnancy cohorts in the world with longitudinal design and detailed and standardised microbiome sampling enabling follow-up of both mothers and children. The findings are expected to contribute greatly to the field of reproductive health focusing on pregnancy and neonatal outcomes.

RevDate: 2022-10-29
CmpDate: 2022-10-28

France MT, Brown SE, Rompalo AM, et al (2022)

Identification of shared bacterial strains in the vaginal microbiota of related and unrelated reproductive-age mothers and daughters using genome-resolved metagenomics.

PloS one, 17(10):e0275908.

It has been suggested that the human microbiome might be vertically transmitted from mother to offspring and that early colonizers may play a critical role in development of the immune system. Studies have shown limited support for the vertical transmission of the intestinal microbiota but the derivation of the vaginal microbiota remains largely unknown. Although the vaginal microbiota of children and reproductive age women differ in composition, the vaginal microbiota could be vertically transmitted. To determine whether there was any support for this hypothesis, we examined the vaginal microbiota of daughter-mother pairs from the Baltimore metropolitan area (ages 14-27, 32-51; n = 39). We assessed whether the daughter's microbiota was similar in composition to their mother's using metataxonomics. Permutation tests revealed that while some pairs did have similar vaginal microbiota, the degree of similarity did not exceed that expected by chance. Genome-resolved metagenomics was used to identify shared bacterial strains in a subset of the families (n = 22). We found a small number of bacterial strains that were shared between mother-daughter pairs but identified more shared strains between individuals from different families, indicating that vaginal bacteria may display biogeographic patterns. Earlier-in-life studies are needed to demonstrate vertical transmission of the vaginal microbiota.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Muñoz-García A, Arbeli Z, Boyacá-Vásquez V, et al (2022)

Metagenomic and genomic characterization of heavy metal tolerance and resistance genes in the rhizosphere microbiome of Avicennia germinans in a semi-arid mangrove forest in the tropics.

Marine pollution bulletin, 184:114204.

Mangroves are often exposed to heavy metals that accumulate in the food chain, generate toxicity to mangrove plants and affect microbial diversity. This study determined the abundance of genes associated with resistance and tolerance to heavy metals in the rhizosphere microbiome of Avicennia germinans from a semi-arid mangrove of La Guajira-Colombia by metagenomics and genomics approach. Twenty-eight genes associated with tolerance and 49 genes related to resistance to heavy metals were detected. Genes associated with tolerance and resistance to Cu, especially cusA and copA, were the most abundant. The highest number of genes for tolerance and resistance were for Zn and Co, respectively. The isolate Vibrio fluvialis showed the ability to tolerate Cu, Ni, Zn, and Cd. This work used a complementary approach of metagenomics and genomics to characterize the potential of mangrove microorganisms to tolerate and resist heavy metals and the influence of salinity on their abundance.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Herrera G, Arboleda JC, Pérez-Jaramillo JE, et al (2022)

Microbial Interdomain Interactions Delineate the Disruptive Intestinal Homeostasis in Clostridioides difficile Infection.

Microbiology spectrum, 10(5):e0050222.

Clostridioides difficile infection (CDI) creates an imbalance in the intestinal microbiota due to the interaction of the components making up this ecosystem, but little is known about the impact of this disease on other microbial members. This work has thus been aimed at evaluating the taxonomic composition, potential gene-associated functions, virulence factors, and antimicrobial resistance profiles of gut microbiomes. A total of 48 DNA samples obtained from patients with health care facility-acquired (HCFO) and community-onset (CO) diarrhea were distributed in the following four groups according to CDI status: HCFO/+ (n = 13), HCFO/- (n = 8), CO/+ (n = 13), and CO/- (n = 14). These samples were subjected to shotgun metagenomics sequencing. Although the CDI groups' microbiota had microbiome alterations, the greatest imbalance was observed in the in the HCFO+/- groups, with an increase in common pathogens and phage populations, as well as a decrease in beneficial microorganisms that leads to a negative impact on some intestinal homeostasis-related metabolic processes. A reduction in the relative abundance of butyrate metabolism-associated genes was also detected in the HCFO groups (P < 0.01), with an increase in some virulence factors and antibiotic-resistance markers. A set of 51 differentially abundant species in the groups with potential association to CDI enabled its characterization, leading to their spatial separation by onset. Strong correlations between phages and some archaeal and bacterial phyla were identified. This highlighted the need to study the microbiota's various components since their imbalance is multifactorial, with some pathogens contributing to a greater or lesser extent because of their interaction with the ecosystem they inhabit. IMPORTANCE Clostridioides difficile infection represents a serious public health problem in different countries due to its high morbi-mortality and the high costs it represents for health care systems. Studies have shown the impact of this infection on intestinal microbiome homeostasis, mainly on bacterial populations. Our research provides evidence of the impact of CDI at both the compositional (bacteria, archaea, and viruses), and functional levels, allowing us to understand that the alterations of the microbiota occur systemically and are caused by multiple perturbations generated by different members of the microbiota as well as by some pathogens that take advantage of the imbalance to proliferate. Likewise, the 51 differentially abundant species in the study groups with potential association to CDI found in this study could help us envisage future treatments against this and other inflammatory diseases, improving future therapeutic options for patients.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Tan Y, Du H, Zhang H, et al (2022)

Geographically Associated Fungus-Bacterium Interactions Contribute to the Formation of Geography-Dependent Flavor during High-Complexity Spontaneous Fermentation.

Microbiology spectrum, 10(5):e0184422.

Fermented foods often have attractive flavor characteristics to meet various human demands. An ever-challenging target is the production of fermented foods with equal flavor profiles outside the product's origin. However, the formation of geography-dependent flavor in high-complexity fermentations remains poorly understood. Here, taking Chinese liquor (baijiu) fermentation as an example, we collected 403 samples from 9 different locations in China across a latitude range of 27°N to 37°N. We revealed and validated the geography-dependent flavor formation patterns by using culture-independent (metabolomics, metagenomics, and metatranscriptomics) and culture-dependent tools. We found that the baijiu microbiomes along with their metabolites were flavor related and geography dependent. The geographical characteristics were determined mainly by 20 to 40 differentiated chemical markers in metabolites and the latitude-dependent fungal structure of the microbiome. About 48 to 156 core microbiota members out of 735 bacterial genera and 290 fungal genera contributed to the chemical markers. The contributions of both fungi and bacteria were greater than those from either bacteria or fungi alone. Representatively, we revealed that dynamic interdependent interactions between yeasts and Lactobacillus facilitated the metabolism of heterocyclic flavor chemicals such as 2-acetylpyrrole, 2,3,5-trimethylpyrazine, and 2-acetylfuran. Moreover, we found that the intraspecific genomic diversity and microbial structure were two biotic factors that contributed to dynamic microbiome assembly. Based on the assembly pattern, adjusting the composition and distribution of initial species was one option to regulate the formation of diverse flavor characteristics. Our study provided a rationale for developing a microbiome design to achieve a defined flavor goal. IMPORTANCE People consume many spontaneously fermented foods and beverages with different flavors on a daily basis. One crucial and hotly discussed question is how to reproduce fermented food flavor without geographical limitations to meet diverse human demands. The constantly enriched knowledge of the microbial contribution to fermented flavor offers valuable insights into flavor biotechnological development. However, we still have a poor understanding of what factors limit the reproduction of fermented flavor outside the product's origin in high-complexity spontaneous fermentations. Here, taking baijiu fermentation as an example, we revealed that geography-dependent flavor was contributed mainly by fungus-bacterium cooperative metabolism. The distinct initial microbial composition, distribution, and intraspecific genomic diversity limited reproducible microbial interactions and metabolism in different geographical areas. The abundant microbial resources and predicted fungus-bacterium interactions found in baijiu fermentation enable us to design a synthetic microbial community to reproduce desired flavor profiles in the future.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Peroumal D, Sahu SR, Kumari P, et al (2022)

Commensal Fungus Candida albicans Maintains a Long-Term Mutualistic Relationship with the Host To Modulate Gut Microbiota and Metabolism.

Microbiology spectrum, 10(5):e0246222.

Candida albicans survives as a commensal fungus in the gastrointestinal tract, and that its excessive growth causes infections in immunosuppressed individuals is widely accepted. However, any mutualistic relationship that may exist between C. albicans and the host remains undetermined. Here, we showed that a long-term feeding of C. albicans does not cause any noticeable infections in the mouse model. Our 16S and 18S ribosomal DNA (rDNA) sequence analyses suggested that C. albicans colonizes in the gut and modulates microbiome dynamics, which in turn mitigates high-fat-diet-induced uncontrolled body weight gain and metabolic hormonal imbalances. Interestingly, adding C. albicans to a nonobesogenic diet stimulated the appetite-regulated hormones and helped the mice maintain a healthy body weight. In concert, our results suggest a mutualism between C. albicans and the host, contrary to the notion that C. albicans is always an adversary and indicating it can instead be a bona fide admirable companion of the host. Finally, we discuss its potential translational implication as a probiotic, especially in obese people or people dependent on high-fat calorie intakes to manage obesity associated complications. IMPORTANCE Candida albicans is mostly considered an opportunistic pathogen that causes fetal systemic infections. However, this study demonstrates that in its commensal state, it maintains a long-term mutualistic relationship with the host and regulates microbial dynamics in the gut and host physiology. Thus, we concluded that C. albicans is not always an adversary but rather can be a bona fide admirable companion of the host. More importantly, as several genomic knockout strains of C. albicans were shown to be avirulent, such candidate strains may be explored further as preferable probiotic isolates to control obesity.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Shi C, Beller L, Wang L, et al (2022)

Bidirectional Interactions between Arboviruses and the Bacterial and Viral Microbiota in Aedes aegypti and Culex quinquefasciatus.

mBio, 13(5):e0102122.

Mosquitoes are important vectors for many arboviruses. It is becoming increasingly clear that various symbiotic microorganisms (including bacteria and insect-specific viruses; ISVs) in mosquitoes have the potential to modulate the ability of mosquitoes to transmit arboviruses. In this study, we compared the bacteriome and virome (both eukaryotic viruses and bacteriophages) of female adult Aedes aegypti and Culex quinquefasciatus mosquitoes fed with sucrose/water, blood, or blood spiked with Zika virus (ZIKV) or West Nile virus (WNV), respectively. Furthermore, we investigated associations between the microbiota and vector competence. We show that the influence of arboviruses on the mosquito microbiome-and vice versa-is distinct for each combination of arbovirus/mosquito species. The presence of ZIKV resulted in a temporarily increased Aedes ISV diversity. However, this effect was distinct for different ISVs: some ISVs decreased following the blood meal (Aedes aegypti totivirus), whereas other ISVs increased only when the blood contained ZIKV (Guadeloupe mosquito virus). Also, the diversity of the Aedes bacteriome depended on the diet and the presence of ZIKV, with a lower diversity observed for mosquitoes receiving blood without ZIKV. In Cx. quinquefasciatus, some ISVs increased in WNV-infected mosquitoes (Guadeloupe Culex tymo-like virus). Particularly, the presence of Wenzhou sobemo-like virus 3 (WSLV3) was associated with the absence of infectious WNV in mosquito heads, suggesting that WSLV3 might affect vector competence for WNV. Distinct profiles of bacteriophages were identified in Culex mosquitoes depending on diet, despite the lack of clear changes in the bacteriome. Overall, our data demonstrate a complex three-way interaction among arboviruses, resident microbiota, and the host, which is distinct for different arbovirus-mosquito combinations. A better understanding of these interactions may lead to the identification of microbiota able to suppress the ability of arbovirus transmission to humans, and hence improved arbovirus control measures. IMPORTANCE In this study, we first utilized the single mosquito microbiome analysis, demonstrating a complex three-way interaction among arboviruses, resident microbiota, and the host, which is distinct for different arbovirus-mosquito combinations. Some of the previously described "core virus" increased in the mosquitos receiving viral blood meal, like Guadeloupe mosquito virus and Guadeloupe Culex tymo-like virus, suggesting their potential roles in ZIKV and WNV infection. Notably, Wenzhou sobemo-like virus 3 was associated with the absence of infectious WNV in heads of Culex mosquitoes, which might affect vector competence for WNV. A better understanding of these interactions will lead to the identification of microbiota able to suppress the ability of arbovirus transmission to humans, and hence improved arbovirus control measures.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Li C, Tang M, Li X, et al (2022)

Community Dynamics in Structure and Function of Honey Bee Gut Bacteria in Response to Winter Dietary Shift.

mBio, 13(5):e0113122.

Temperate honey bees (Apis mellifera) are challenged by low temperatures and abrupt dietary shifts associated with behavioral changes during winter. Case studies have revealed drastic turnover in the gut microbiota of winter bees, highlighted by the seasonal dominance of a non-core bacterium Bartonella. However, neither biological consequence nor underlying mechanism of this microbial turnover is clear. In particular, we ask whether such changes in gut profile are related to winter dietary shift and possibly beneficial to host and associated gut microbiome? Here, we integrated evidences from genomics, metagenomics, and metabolomics in three honey bee subspecies maintained at the same locality of northern China to profile both diversity and functional variations in gut bacteria across seasons. Our results showed that winter dominance of Bartonella was shared in all tested honey bee lineages. This seasonal change was likely a consequence of winter dietary shifts characterized by greatly reduced pollen consumption and accumulation of metabolic waste due to restricted excretion. Bartonella showed expanded genomic capacity in utilizing more diverse energy substrates, such as converting metabolic wastes lactate and ethanol into pyruvate, an energy source for self-utilization and possibly also for host and other symbionts. Furthermore, Bartonella was the only bacterium capable of both producing and secreting tryptophan and phenylalanine, whose metabolic products were detected in bee guts, even though all gut bacteria lacked relevant digestion enzymes. These results thus suggested a possible mechanism where the gut bacteria might benefit the host by supplementing them with essential amino acids lacking in a protein shortage diet. IMPORTANCE The abilities to survive winter and to adapt to major food changes are key traits that have enabled successful range expansion of the honey bees from the tropic to temperate climate. Our results highlighted a new possibility that gut bacteria may have played an important role in host survival of the severe winter condition. The non-core bacterium Bartonella is not only more adaptive to the winter diet but is also equipped with the capacity to provide the host with essential nutrients and important metabolic substrates. This overall host-bacterium profile is probably favored by natural selection, resulting in a consistent winter gut strategy across varied honey bee lineages. Conversely, when the hosts start to forage again, core bacteria maintained at low abundance during winter returned to their typical dominant status, thus completing the annual gut turnover. Our study suggests a new hypothesis where seasonal gut variations may improve the fitness of the honey bee, allowing them to explore more diverse climates.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Rout AK, Dehury B, Parida PK, et al (2022)

Taxonomic profiling and functional gene annotation of microbial communities in sediment of river Ganga at Kanpur, India: insights from whole-genome metagenomics study.

Environmental science and pollution research international, 29(54):82309-82323.

The perennial river Ganga is recognized as one of India's largest rivers of India, but due to continuous anthropogenic activities, the river's ecosystem is under threat. Next-generation sequencing technology has transformed metagenomics in the exploration of microbiome and their imperative function in diverse aquatic ecosystems. In this study, we have uncovered the structure of community microbiome and their functions in sediments of river Ganga at Kanpur, India, at three polluted stretches through a high-resolution metagenomics approach using Illumina HiSeq 2500. Among the microbes, bacteria dominate more than 82% in the three polluted sediment samples of river Ganga. Pseudomonadota (alpha, beta, and gamma) is the major phylum of bacteria that dominates in three sediment samples. Genes involved in degradation of xenobiotic compounds involving nitrotoluene, benzoate, aminobenzoate, chlorocyclohexane, and chlorobenzene were significantly enriched in the microbiome of polluted stretches. Pathway analysis using KEGG database revealed a higher abundance of genes involved in energy metabolism such as oxidative phosphorylation, nitrogen, methane, sulfur, and carbon fixation pathways in the sediment metagenome data from the river Ganga. A higher abundance of pollutant degrading enzymes like 4-hydroxybenzoate 3-monooxygenase, catalase-peroxidase, and altronate hydrolase in the polluted microbiome indicates their role in degradation of plastics and dyes. Overall, our study has provided bacterial diversity and their dynamics in community structure and function from polluted river microbiome, which is expected to open up better avenues for exploration of novel functional genes/enzymes with potential application in health and bioremediation.

RevDate: 2022-10-27

Leite MFA, van den Broek SWEB, EE Kuramae (2022)

Current Challenges and Pitfalls in Soil Metagenomics.

Microorganisms, 10(10): pii:microorganisms10101900.

Soil microbial communities are essential components of agroecological ecosystems that influence soil fertility, nutrient turnover, and plant productivity. Metagenomics data are increasingly easy to obtain, but studies of soil metagenomics face three key challenges: (1) accounting for soil physicochemical properties; (2) incorporating untreated controls; and (3) sharing data. Accounting for soil physicochemical properties is crucial for better understanding the changes in soil microbial community composition, mechanisms, and abundance. Untreated controls provide a good baseline to measure changes in soil microbial communities and separate treatment effects from random effects. Sharing data increases reproducibility and enables meta-analyses, which are important for investigating overall effects. To overcome these challenges, we suggest establishing standard guidelines for the design of experiments for studying soil metagenomics. Addressing these challenges will promote a better understanding of soil microbial community composition and function, which we can exploit to enhance soil quality, health, and fertility.

RevDate: 2022-10-27

Ferrandi EE, Bassanini I, Bertuletti S, et al (2022)

Functional Characterization and Synthetic Application of Is2-SDR, a Novel Thermostable and Promiscuous Ketoreductase from a Hot Spring Metagenome.

International journal of molecular sciences, 23(20): pii:ijms232012153.

In a metagenome mining-based search of novel thermostable hydroxysteroid dehydrogenases (HSDHs), enzymes that are able to selectively oxidize/reduce steroidal compounds, a novel short-chain dehydrogenase/reductase (SDR), named Is2-SDR, was recently discovered. This enzyme, found in an Icelandic hot spring metagenome, shared a high sequence similarity with HSDHs, but, unexpectedly, showed no activity in the oxidation of the tested steroid substrates, e.g., cholic acid. Despite that, Is2-SDR proved to be a very active and versatile ketoreductase, being able to regio- and stereoselectively reduce a diversified panel of carbonylic substrates, including bulky ketones, α- and β-ketoesters, and α-diketones of pharmaceutical relevance. Further investigations showed that Is2-SDR was indeed active in the regio- and stereoselective reduction of oxidized steroid derivatives, and this outcome was rationalized by docking analysis in the active site model. Moreover, Is2-SDR showed remarkable thermostability, with an apparent melting temperature (TM) around 75 °C, as determined by circular dichroism analysis, and no significant decrease in catalytic activity, even after 5 h at 80 °C. A broad tolerance to both water-miscible and water-immiscible organic solvents was demonstrated as well, thus, confirming the potential of this new biocatalyst for its synthetic application.

RevDate: 2022-10-27
CmpDate: 2022-10-27

von Takach B, Ranjard L, Burridge CP, et al (2022)

Population genomics of a predatory mammal reveals patterns of decline and impacts of exposure to toxic toads.

Molecular ecology, 31(21):5468-5486.

Mammal declines across northern Australia are one of the major biodiversity loss events occurring globally. There has been no regional assessment of the implications of these species declines for genomic diversity. To address this, we conducted a species-wide assessment of genomic diversity in the northern quoll (Dasyurus hallucatus), an Endangered marsupial carnivore. We used next generation sequencing methods to genotype 10,191 single nucleotide polymorphisms (SNPs) in 352 individuals from across a 3220-km length of the continent, investigating patterns of population genomic structure and diversity, and identifying loci showing signals of putative selection. We found strong heterogeneity in the distribution of genomic diversity across the continent, characterized by (i) biogeographical barriers driving hierarchical population structure through long-term isolation, and (ii) severe reductions in diversity resulting from population declines, exacerbated by the spread of introduced toxic cane toads (Rhinella marina). These results warn of a large ongoing loss of genomic diversity and associated adaptive capacity as mammals decline across northern Australia. Encouragingly, populations of the northern quoll established on toad-free islands by translocations appear to have maintained most of the initial genomic diversity after 16 years. By mapping patterns of genomic diversity within and among populations, and investigating these patterns in the context of population declines, we can provide conservation managers with data critical to informed decision-making. This includes the identification of populations that are candidates for genetic management, the importance of remnant island and insurance/translocated populations for the conservation of genetic diversity, and the characterization of putative evolutionarily significant units.

RevDate: 2022-10-27
CmpDate: 2022-10-27

Li J, Jin J, Li S, et al (2022)

Tonsillar Microbiome-Derived Lantibiotics Induce Structural Changes of IL-6 and IL-21 Receptors and Modulate Host Immunity.

Advanced science (Weinheim, Baden-Wurttemberg, Germany), 9(30):e2202706.

Emerging evidence emphasizes the functional impacts of host microbiome on the etiopathogenesis of autoimmune diseases, including rheumatoid arthritis (RA). However, there are limited mechanistic insights into the contribution of microbial biomolecules especially microbial peptides toward modulating immune homeostasis. Here, by mining the metagenomics data of tonsillar microbiome, a deficiency of the encoding genes of lantibiotic peptides salivaricins in RA patients is identified, which shows strong correlation with circulating immune cells. Evidence is provided that the salivaricins exert immunomodulatory effects in inhibiting T follicular helper (Tfh) cell differentiation and interleukin-21 (IL-21) production. Mechanically, salivaricins directly bind to and induce conformational changes of IL-6 and IL-21 receptors, thereby inhibiting the bindings of IL-6 and IL-21 to their receptors and suppressing the downstream signaling pathway. Finally, salivaricin administration exerts both prophylactic and therapeutic effects against experimental arthritis in a murine model of RA. Together, these results provide a mechanism link of microbial peptides-mediated immunomodulation.

RevDate: 2022-10-26
CmpDate: 2022-10-26

Muscatt G, Hilton S, Raguideau S, et al (2022)

Crop management shapes the diversity and activity of DNA and RNA viruses in the rhizosphere.

Microbiome, 10(1):181.

BACKGROUND: The rhizosphere is a hotspot for microbial activity and contributes to ecosystem services including plant health and biogeochemical cycling. The activity of microbial viruses, and their influence on plant-microbe interactions in the rhizosphere, remains undetermined. Given the impact of viruses on the ecology and evolution of their host communities, determining how soil viruses influence microbiome dynamics is crucial to build a holistic understanding of rhizosphere functions.

RESULTS: Here, we aimed to investigate the influence of crop management on the composition and activity of bulk soil, rhizosphere soil, and root viral communities. We combined viromics, metagenomics, and metatranscriptomics on soil samples collected from a 3-year crop rotation field trial of oilseed rape (Brassica napus L.). By recovering 1059 dsDNA viral populations and 16,541 ssRNA bacteriophage populations, we expanded the number of underexplored Leviviricetes genomes by > 5 times. Through detection of viral activity in metatranscriptomes, we uncovered evidence of "Kill-the-Winner" dynamics, implicating soil bacteriophages in driving bacterial community succession. Moreover, we found the activity of viruses increased with proximity to crop roots, and identified that soil viruses may influence plant-microbe interactions through the reprogramming of bacterial host metabolism. We have provided the first evidence of crop rotation-driven impacts on soil microbial communities extending to viruses. To this aim, we present the novel principal of "viral priming," which describes how the consecutive growth of the same crop species primes viral activity in the rhizosphere through local adaptation.

CONCLUSIONS: Overall, we reveal unprecedented spatial and temporal diversity in viral community composition and activity across root, rhizosphere soil, and bulk soil compartments. Our work demonstrates that the roles of soil viruses need greater consideration to exploit the rhizosphere microbiome for food security, food safety, and environmental sustainability. Video Abstract.

RevDate: 2022-10-26
CmpDate: 2022-10-26

Afzal S, NK Singh (2022)

Effect of zinc and iron oxide nanoparticles on plant physiology, seed quality and microbial community structure in a rice-soil-microbial ecosystem.

Environmental pollution (Barking, Essex : 1987), 314:120224.

In this study, we assessed the impact of zinc oxide (ZnO) and iron oxide (FeO) (<36 nm) nanoparticles (NPs) as well as their sulphate salt (bulk) counterpart (0, 25, 100 mg/kg) on rice growth and seed quality as well as the microbial community in the rhizosphere environment of rice. During the rice growing season 2021-22, all experiments were conducted in a greenhouse (temperature: day 30 °C; night 20 °C; relative humidity: 70%; light period: 16 h/8 h, day/night) in rice field soil. Results showed that low concentrations of FeO and ZnO NPs (25 mg/kg) promoted rice growth (height (29%, 16%), pigment content (2%, 3%)) and grain quality parameters such as grains per spike (8%, 9%), dry weight of grains (12%, 14%) respectively. As compared to the control group, the Zn (2%) and Fe (5%) accumulations at their respective low concentrations of NP treatments showed stimulation. Interestingly, our results showed that at low concentration of both the NPs the soil microbes had more diversity and richness than those in the bulk treated and control soil group. Although a number of phyla were affected by the presence of NPs, the strongest effects were observed for change in the abundance of the three phyla for Proteobacteria, Actinobacteria, and Planctomycetes. The rhizosphere environment was notably enriched with potential streptomycin producers, carbon and nitrogen fixers, and lignin degraders with regard to functional groups of microorganisms. However, microbial communities mainly responsible for chitin degradation, ammonia oxidation, and nitrite reduction were found to be decreased. The results from this study highlight significant changes in several plant-based endpoints, as well as the rhizosphere soil microorganisms. It further adds information to our understanding of the nanoscale-specific impacts of important micronutrient oxides on both rice and its associated soil microbiome.

RevDate: 2022-10-25

Garrido-Sanz L, Àngel Senar M, J Piñol (2022)

Drastic reduction of false positive species in samples of insects by intersecting the default output of two popular metagenomic classifiers.

PloS one, 17(10):e0275790 pii:PONE-D-22-10594.

The use of high-throughput sequencing to recover short DNA reads of many species has been widely applied on biodiversity studies, either as amplicon metabarcoding or shotgun metagenomics. These reads are assigned to taxa using classifiers. However, for different reasons, the results often contain many false positives. Here we focus on the reduction of false positive species attributable to the classifiers. We benchmarked two popular classifiers, BLASTn followed by MEGAN6 (BM) and Kraken2 (K2), to analyse shotgun sequenced artificial single-species samples of insects. To reduce the number of misclassified reads, we combined the output of the two classifiers in two different ways: (1) by keeping only the reads that were attributed to the same species by both classifiers (intersection approach); and (2) by keeping the reads assigned to some species by any classifier (union approach). In addition, we applied an analytical detection limit to further reduce the number of false positives species. As expected, both metagenomic classifiers used with default parameters generated an unacceptably high number of misidentified species (tens with BM, hundreds with K2). The false positive species were not necessarily phylogenetically close, as some of them belonged to different orders of insects. The union approach failed to reduce the number of false positives, but the intersection approach got rid of most of them. The addition of an analytic detection limit of 0.001 further reduced the number to ca. 0.5 false positive species per sample. The misidentification of species by most classifiers hampers the confidence of the DNA-based methods for assessing the biodiversity of biological samples. Our approach to alleviate the problem is straightforward and significantly reduced the number of reported false positive species.

RevDate: 2022-10-25
CmpDate: 2022-10-25

Sato Y, Takebe H, Oishi K, et al (2022)

Identification of 146 Metagenome-assembled Genomes from the Rumen Microbiome of Cattle in Japan.

Microbes and environments, 37(4):.

The rumen contains a complex microbial ecosystem that degrades plant materials, such as cellulose and hemicellulose. We herein reconstructed 146 nonredundant, rumen-specific metagenome-assembled genomes (MAGs), with ≥50% completeness and <10% contamination, from cattle in Japan. The majority of MAGs were potentially novel strains, encoding various enzymes related to plant biomass degradation and volatile fatty acid production. The MAGs identified in the present study may be valuable resources to enhance the resolution of future taxonomical and functional studies based on metagenomes and metatranscriptomes.

RevDate: 2022-10-25
CmpDate: 2022-10-25

Ghosh TS, M Das (2022)

Emerging tools for understanding the human microbiome.

Progress in molecular biology and translational science, 191(1):29-51.

Recent advances in sequencing technologies, experimental protocols and approaches in data generation and analysis have enabled us to investigate the human microbiome at an unprecedented level of resolution. The current chapter aims to provide an understanding of the different computational and bioinformatic strategies adopted to answer the different questions of a typical microbiome investigation and how the upstream DNA sequencing methodologies can affect this. The chapter enlist the state-of-the-art in metagenomic data analysis along with the available strategies to perform an integrated investigation of the human microbiome along with other data layers.

RevDate: 2022-10-25
CmpDate: 2022-10-25

de Diego GA, Penas-Steinhardt A, Ferro JP, et al (2022)

Impact of exposure to arsenic on the bacterial microbiota associated with river biofilms in the Pampas region.

Aquatic toxicology (Amsterdam, Netherlands), 252:106319.

Freshwater contamination by arsenic (As) is a worldwide problem. It may be found in Pampean streams of Argentina at concentrations higher than those recommended by international organizations and stipulated by national regulations. Exposure to high As concentrations causes serious consequences to both human health and the environment. The general objective of this work was to evaluate the effect of As on the biofilm microbiota structure from Naveira stream, Luján, Province of Buenos Aires (Coordinates: 34º34'02″ S 59º03'51″ W). The biofilm collected was cultivated in glass aquaria at different As III concentrations (0, 0.2 and 20 mg / L), inside incubation chambers under controlled conditions (16 h light: 8 h dark and 24 ± 1 °C) and constant aeration for 31 d, with partial water renewal every 9 d. We amplified the hypervariable regions V3 and V4 of the bacterial 16S rRNA gene from biofilm bacterial community samples to determine the diversity and abundance of the different taxa. The taxonomic composition of each sample, the alpha diversity of each treatment and the main metabolic pathways were analyzed. Principal Component Analysis of the present phyla and a Linear Discriminant Analysis of the metabolic pathways was also performed. Significant changes were observed in relation to the taxonomic composition of the bacterial community after exposure to the metalloid. However, this effect was not observed at the low concentration used (0.2 mg / L), which is the one that corresponds to ecologically relevant levels. The significantly affected phyla were Verrucomicrobiota, Acidobacteriota, Patescibacteria, Hydrogenedentes and WPS-2. The relative abundances of the Verrucomicrobiota, WPS-2 and Patescibacteria groups were notably decreased in the treatment with high As, while the Acidobacteria group was increased in both treatments with As. The stream samples showed greater bacterial diversity than those grown in the laboratory without As. Finally, it was possible to characterize the metabolic profile of the biofilm developed under natural conditions in the leaves of the aquatic plant Elodea canadensis in the Naveira stream. In addition, results showed that biosynthesis-related pathways were more abundant at the high As concentration treatment (20 mg / L).

RevDate: 2022-10-25
CmpDate: 2022-10-25

Fan L, Zhu X, Sun S, et al (2022)

Ca:Mg ratio, medium-chain fatty acids, and the gut microbiome.

Clinical nutrition (Edinburgh, Scotland), 41(11):2490-2499.

BACKGROUND & AIMS: Ketogenic medium-chain fatty acids (MCFAs) with profound health benefits are commonly found in dairy products, palm kernel oil and coconut oil. We hypothesize that magnesium (Mg) supplementation leads to enhanced gut microbial production of MCFAs and, in turn, increased circulating MCFAs levels.

METHODS: We tested this hypothesis in the Personalized Prevention of Colorectal Cancer Trial (PPCCT) (NCT01105169), a double-blind 2 × 2 factorial randomized controlled trial enrolling 240 participants. Six 24-h dietary recalls were performed for all participants at the baseline and during the intervention period. Based on the baseline 24-h dietary recalls, the Mg treatment used a personalized dose of Mg supplementation that would reduce the calcium (Ca): Mg intake ratio to around 2.3. We measured plasma MCFAs, sugars, ketone bodies and tricarboxylic acid cycle (TCA cycle) metabolites using the Metabolon's global Precision Metabolomics™ LC-MS platform. Whole-genome shotgun metagenomics (WGS) sequencing was performed to assess microbiota in stool samples, rectal swabs, and rectal biopsies.

RESULTS: Personalized Mg treatment (mean dose 205.58 mg/day with a range from 77.25 to 389.55 mg/day) significantly increased the plasma levels of C7:0, C8:0, and combined C7:0 and C8:0 by 18.45%, 25.28%, and 24.20%, respectively, compared to 14.15%, 10.12%, and 12.62% decreases in the placebo arm. The effects remain significant after adjusting for age, sex, race and baseline level (P = 0.0126, P = 0.0162, and P = 0.0031, respectively) and FDR correction at 0.05 (q = 0.0324 for both C7:0 and C8:0). Mg treatment significantly reduced the plasma level of sucrose compared to the placebo arm (P = 0.0036 for multivariable-adjusted and P = 0.0216 for additional FDR correction model) whereas alterations in daily intakes of sucrose, fructose, glucose, maltose and C8:0 from baseline to the end of trial did not differ between two arms. Mediation analysis showed that combined C7:0 and C8:0 partially mediated the effects of Mg treatment on total and individual ketone bodies (P for indirect effect = 0.0045, 0.0043, and 0.03, respectively). The changes in plasma levels of C7:0 and C8:0 were significantly and positively correlated with the alterations in stool microbiome α diversity (r = 0.51, p = 0.0023 and r = 0.34, p = 0.0497, respectively) as well as in stool abundance for the signatures of MCFAs-related microbiota with acyl-ACP thioesterase gene producing C7:0 (r = 0.46, p = 0.0067) and C8:0 (r = 0.49, p = 0.003), respectively, following Mg treatment.

CONCLUSIONS: Optimizing Ca:Mg intake ratios to around 2.3 through 12-week personalized Mg supplementation leads to increased circulating levels of MCFAs (i.e. C7:0 and C8:0), which is attributed to enhanced production from gut microbial fermentation and, maybe, sucrose consumption.

RevDate: 2022-10-25
CmpDate: 2022-10-25

Thompson DS, Fu C, Gandhi T, et al (2023)

Differential co-expression networks of the gut microbiota are associated with depression and anxiety treatment resistance among psychiatric inpatients.

Progress in neuro-psychopharmacology & biological psychiatry, 120:110638.

BACKGROUND: Comorbid anxiety and depression are common and are associated with greater disease burden than either alone. Our recent efforts have identified an association between gut microbiota dysfunction and severity of anxiety and depression. In this follow-up, we applied Differential Co-Expression Analysis (DiffCoEx) to identify potential gut microbiota biomarker(s) candidates of treatment resistance among psychiatric inpatients.

METHODS: In a sample of convenience, 100 psychiatric inpatients provided clinical data at admission and discharge; fecal samples were collected early during the hospitalization. Whole genome shotgun sequencing methods were used to process samples. DiffCoEx was used to identify clusters of microbial features significantly different based on treatment resistance status. Once overlapping features were identified, a knowledge-mining tool was used to review the literature using a list of microbial species/pathways and a select number of medical subject headlines (MeSH) terms relevant for depression, anxiety, and brain-gut-axis dysregulation. Network analysis used overlapping features to identify microbial interactions that could impact treatment resistance.

RESULTS: DiffCoEx analyzed 10,403 bacterial features: 43/44 microbial features associated with depression treatment resistance overlapped with 43/114 microbial features associated with anxiety treatment resistance. Network analysis resulted in 8 biological interactions between 16 bacterial species. Clostridium perfringens evidenced the highest connection strength (0.95). Erysipelotrichaceae bacterium 6_1_45 has been most widely examined, is associated with inflammation and dysbiosis, but has not been associated with depression or anxiety.

CONCLUSION: DiffCoEx potentially identified gut bacteria biomarker candidates of depression and anxiety treatment-resistance. Future efforts in psychiatric microbiology should examine the mechanistic relationship of identified pro-inflammatory species, potentially contributing to a biomarker-based algorithm for treatment resistance.

RevDate: 2022-10-24
CmpDate: 2022-10-24

Khorsand B, Asadzadeh Aghdaei H, Nazemalhosseini-Mojarad E, et al (2022)

Overrepresentation of Enterobacteriaceae and Escherichia coli is the major gut microbiome signature in Crohn's disease and ulcerative colitis; a comprehensive metagenomic analysis of IBDMDB datasets.

Frontiers in cellular and infection microbiology, 12:1015890.

Objectives: A number of converging strands of research suggest that the intestinal Enterobacteriaceae plays a crucial role in the development and progression of inflammatory bowel disease (IBD), however, the changes in the abundance of Enterobacteriaceae species and their related metabolic pathways in Crohn's disease (CD) and ulcerative colitis (UC) compared to healthy people are not fully explained by comprehensive comparative metagenomics analysis. In the current study, we investigated the alternations of the Enterobacterales population in the gut microbiome of patients with CD and UC compared to healthy subjects.

Methods: Metagenomic datasets were selected from the Integrative Human Microbiome Project (HMP2) through the Inflammatory Bowel Disease Multi'omics Database (IBDMDB). We performed metagenome-wide association studies on fecal samples from 191 CD patients, 132 UC patients, and 125 healthy controls (HCs). We used the metagenomics dataset to study bacterial community structure, relative abundance, differentially abundant bacteria, functional analysis, and Enterobacteriaceae-related biosynthetic pathways.

Results: Compared to the gut microbiome of HCs, six Enterobacteriaceae species were significantly elevated in both CD and UC patients, including Escherichia coli, Klebsiella variicola, Klebsiella quasipneumoniae, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter freundii, and Citrobacter youngae, while Klebsiella oxytoca, Morganella morganii, and Citrobacter amalonaticus were uniquely differentially abundant and enriched in the CD cohort. Four species were uniquely differentially abundant and enriched in the UC cohort, including Citrobacter portucalensis, Citrobacter pasteurii, Citrobacter werkmanii, and Proteus hauseri. Our analysis also showed a dramatically increased abundance of E. coli in their intestinal bacterial community. Biosynthetic pathways of aerobactin siderophore, LPS, enterobacterial common antigen, nitrogen metabolism, and sulfur relay systems encoded by E. coli were significantly elevated in the CD samples compared to the HCs. Menaquinol biosynthetic pathways were associated with UC that belonged to K. pneumoniae strains.

Conclusions: In conclusion, compared with healthy people, the taxonomic and functional composition of intestinal bacteria in CD and UC patients was significantly shifted to Enterobacteriaceae species, mainly E. coli and Klebsiella species.

RevDate: 2022-10-24
CmpDate: 2022-10-24

Lin S, Li Q, Xu Z, et al (2022)

Detection of the role of intestinal flora and tryptophan metabolism involved in antidepressant-like actions of crocetin based on a multi-omics approach.

Psychopharmacology, 239(11):3657-3677.

RATIONALE: Depression is a serious mood disorder, and crocetin has a variety of pharmacological activities, including antidepressant effect. The alterations of intestinal flora have a significant correlation with depression, and crocetin can alter the composition of intestinal flora in mice with depression-like behaviors.

OBJECTIVE: This study investigated the underlying antidepressant mechanisms of crocetin through multi-omics coupled with biochemical technique validation.

METHODS: Chronic unpredictable stress (CUMS) was used to induce mice model of depression to evaluate the antidepressant effect of crocetin through behavioral tests, and the metagenomic and metabolomic were used to explore the potential mechanisms involved. In order to verify its underlying mechanism, western blot (WB), Elisa, immune histological and HPLC techniques were used to detect the level of inflammatory cytokines and the level of metabolites/proteins related to tryptophan metabolism in crocetin-treated mice.

RESULTS: Crocetin ameliorated depression-like behaviors and increased mobility in depressive mice induced by CUMS. Metagenomic results showed that crocetin regulated the structure of intestinal flora, as well as significantly regulated the function gene related to derangements in energy metabolism and amino acid metabolism in mice with depression-like behaviors. Metabolomic results showed that the tryptophan metabolism, arginine metabolism and arachidonic acid metabolism played an essential role in exerting antidepressant-like effect of crocetin. According to multi-omics approaches and validation results, tryptophan metabolism and inflammation were identified and validated as valuable biological processes involved in the antidepressant effects of crocetin. Crocetin regulated the tryptophan metabolism in mice with depression-like behaviors, including increased aryl hydrocarbon receptor (AhR) expression, reduced indoleamine 2,3-dioxygenase 1 (IDO1) and serotonin transporter (SERT) expression in the hippocampus, elevated the content of 5-HT, kynurenic acid in serum and 5-HT, tryptophan in hippocampus. In addition, crocetin also attenuated inflammation in mice with depression-like behaviors, which presented with reducing the production of inflammatory cytokines in serum and colon. Meanwhile, crocetin up-regulated the expression of zonula occludens 1 (ZO-1) and occludin in ileum and colon to repair the intestinal barrier for preventing inflammation transfer.

CONCLUSION: Our findings clarify that crocetin exerted antidepressant effects through its anti-inflammation, repairment of intestinal barrier, modulatory on the intestinal flora and metabolic disorders, which further regulated tryptophan metabolism and impacted mitogen-activated protein kinase (MAPK) signaling pathway to enhance neural plasticity, thereby protect neural.

RevDate: 2022-10-24
CmpDate: 2022-10-24

Cui J, Ramesh G, Wu M, et al (2022)

Butyrate-Producing Bacteria and Insulin Homeostasis: The Microbiome and Insulin Longitudinal Evaluation Study (MILES).

Diabetes, 71(11):2438-2446.

Gut microbiome studies have documented depletion of butyrate-producing taxa in type 2 diabetes. We analyzed associations between butyrate-producing taxa and detailed measures of insulin homeostasis, whose dysfunction underlies diabetes in 224 non-Hispanic Whites and 129 African Americans, all of whom completed an oral glucose tolerance test. Stool microbiome was assessed by whole-metagenome shotgun sequencing with taxonomic profiling. We examined associations among 36 butyrate-producing taxa (n = 7 genera and 29 species) and insulin sensitivity, insulin secretion, disposition index, insulin clearance, and prevalence of dysglycemia (prediabetes plus diabetes, 46% of cohort), adjusting for age, sex, BMI, and race. The genus Coprococcus was associated with higher insulin sensitivity (β = 0.14; P = 0.002) and disposition index (β = 0.12; P = 0.012) and a lower rate of dysglycemia (odds ratio [OR] 0.91; 95% CI 0.85-0.97; P = 0.0025). In contrast, Flavonifractor was associated with lower insulin sensitivity (β = -0.13; P = 0.004) and disposition index (β = -0.11; P = 0.04) and higher prevalence of dysglycemia (OR 1.22; 95% CI 1.08-1.38; P = 0.0013). Species-level analyses found 10 bacteria associated with beneficial directions of effects and two bacteria with adverse associations on insulin homeostasis and dysglycemia. Although most butyrate producers analyzed appear to be metabolically beneficial, this is not the case for all such bacteria, suggesting that microbiome-directed therapeutic measures to prevent or treat diabetes should be targeted to specific butyrate-producing taxa rather than all butyrate producers.

RevDate: 2022-10-22

Brennan GL (2022)

Sequencing our way to more accurate community abundance.

Molecular ecology resources [Epub ahead of print].

Over the last two decades, there has been a huge increase in our understanding of microbial diversity, structure and composition enabled by high-throughput sequencing technologies. Yet, it is unclear how the number of sequences translates to the number of cells or species within the community. In some cases, additional observational data may be required to ensure relative abundance patterns from sequence reads are biologically meaningful. The goal of DNA-based methods for biodiversity assessments is to obtain robust community abundance data, simultaneously, from environmental samples. In this issue of Molecular Ecology Resources, Pierella Karlusich et al. (2022) describe a new method for quantifying phytoplankton cell abundance. Using Tara Oceans data sets, the authors propose the photosynthetic gene psbO for reporting accurate relative abundance of the entire phytoplankton community from metagenomic data. The authors demonstrate higher correlations with traditional optical methods (including microscopy and flow cytometry), using their new method, improving upon molecular abundance assessments using multicopy marker genes. Furthermore, to facilitate application of their approach, the authors curated a psbO gene database for accessible taxonomic queries. This is an important step towards improving species abundance estimates from molecular data and eventually reporting of absolute species abundance, enhancing our understanding of community dynamics.

RevDate: 2022-10-21
CmpDate: 2022-10-21

Neugent ML, Kumar A, Hulyalkar NV, et al (2022)

Recurrent urinary tract infection and estrogen shape the taxonomic ecology and function of the postmenopausal urogenital microbiome.

Cell reports. Medicine, 3(10):100753.

Postmenopausal women are severely affected by recurrent urinary tract infection (rUTI). The urogenital microbiome is a key component of the urinary environment. However, changes in the urogenital microbiome underlying rUTI susceptibility are unknown. Here, we perform shotgun metagenomics and advanced culture on urine from a controlled cohort of postmenopausal women to identify urogenital microbiome compositional and function changes linked to rUTI susceptibility. We identify candidate taxonomic biomarkers of rUTI susceptibility in postmenopausal women and an enrichment of lactobacilli in postmenopausal women taking estrogen hormone therapy. We find robust correlations between Bifidobacterium and Lactobacillus and urinary estrogens in women without urinary tract infection (UTI) history. Functional analyses reveal distinct metabolic and antimicrobial resistance gene (ARG) signatures associated with rUTI. Importantly, we find that ARGs are enriched in the urogenital microbiomes of women with rUTI history independent of current UTI status. Our data suggest that rUTI and estrogen shape the urogenital microbiome in postmenopausal women.

RevDate: 2022-10-19
CmpDate: 2022-10-19

Wang Z, Zhang W, Xing X, et al (2022)

Effects of ferroferric oxide on propionate methanogenesis in sequencing batch reactors: Microbial community structure and metagenomic analysis.

Bioresource technology, 363:127909.

This study investigated the effects of ferroferric oxide (Fe3O4) on propionate methanogenesis in anaerobic sequencing batch reactor (ASBR). Compared to ASBRC (without Fe3O4 addition), the addition of 10 g/L Fe3O4 (ASBRFe) decreased the maximum methane production rate by 69.6 % when propionate was used as the sole substrate. The addition of Fe3O4 reduced the contents of humic substances, riboflavin and nicotinamide adenine dinucleotide in extracellular polymeric substances. Therefore, Fe3O4 inhibited interspecies electron transfer of microorganisms through electronic mediators. Microbial community analysis revealed that Fe3O4 addition increased the relative abundance of acetate oxidizing bacterium (Mesotoga), but decreased the abundance of hydrogenotrophic methanogen (Methanobacterium). Further metagenomics analysis indicated that Fe3O4 increased the abundance of acetate oxidation genes and decreased that of hydrogenotrophic methanogenesis, quorum sensing and V/A-type ATPase genes. Thus, Fe3O4 reduced propionate methanogenesis during anaerobic digestion. The overall results indicate that Fe3O4 addition inhibits methanogenesis for treatment of propionate-contaminated wastewater in ASBR.

RevDate: 2022-10-18
CmpDate: 2022-10-18

Thomann AK, Wüstenberg T, Wirbel J, et al (2022)

Depression and fatigue in active IBD from a microbiome perspective-a Bayesian approach to faecal metagenomics.

BMC medicine, 20(1):366.

BACKGROUND: Extraintestinal symptoms are common in inflammatory bowel diseases (IBD) and include depression and fatigue. These are highly prevalent especially in active disease, potentially due to inflammation-mediated changes in the microbiota-gut-brain axis. The aim of this study was to investigate the associations between structural and functional microbiota characteristics and severity of fatigue and depressive symptoms in patients with active IBD.

METHODS: We included clinical data of 62 prospectively enrolled patients with IBD in an active disease state. Patients supplied stool samples and completed the questionnaires regarding depression and fatigue symptoms. Based on taxonomic and functional metagenomic profiles of faecal gut microbiota, we used Bayesian statistics to investigate the associative networks and triangle motifs between bacterial genera, functional modules and symptom severity of self-reported fatigue and depression.

RESULTS: Associations with moderate to strong evidence were found for 3 genera (Odoribacter, Anaerotruncus and Alistipes) and 3 functional modules (pectin, glycosaminoglycan and central carbohydrate metabolism) with regard to depression and for 4 genera (Intestinimonas, Anaerotruncus, Eubacterium and Clostridiales g.i.s) and 2 functional modules implicating amino acid and central carbohydrate metabolism with regard to fatigue.

CONCLUSIONS: This study provides the first evidence of association triplets between microbiota composition, function and extraintestinal symptoms in active IBD. Depression and fatigue were associated with lower abundances of short-chain fatty acid producers and distinct pathways implicating glycan, carbohydrate and amino acid metabolism. Our results suggest that microbiota-directed therapeutic approaches may reduce fatigue and depression in IBD and should be investigated in future research.

RevDate: 2022-10-18
CmpDate: 2022-10-18

Thompson TP, Megaw J, Kelly SA, et al (2022)

Microbial communities of halite deposits and other hypersaline environments.

Advances in applied microbiology, 120:1-32.

Large regions of Earth's surface are underlain by salt deposits that evaporated from ancient oceans and are populated by extreme halophilic microbes. While the microbiology of ancient evaporites has been well studied, the ecology of halite deposits and more recently formed NaCl "salticle" stalactite structures (speleothems) in a Triassic halite mine are less well characterized. The microbiome of Kilroot Salt Mine was profiled using conventional and enhanced culturing techniques. From this, 89 halophilic archaeal isolates from six known genera, and 55 halophilic or halotolerant bacterial isolates from 18 genera were obtained. Culture-independent metagenomic approaches also revealed that culturing techniques were inadvertently biased toward specific taxa, and the need for optimized isolation procedures are required to enhance cultivation diversity. Speleothems formed from saturated brines are unique structures that have the potential to entomb haloarchaea cells for thousands of years within fluid inclusions. The presence of such fluid inclusions, alongside the high abundance of genes related to glycerol metabolism, biofilm formation, and persister cell formation is highly suggestive of an environmental niche that could promote longevity and survivability. Finally, previous studies reporting the discovery of novel biocatalysts from the Kilroot mine microbiome, suggests that this environment may be an untapped source of chemical diversity with high biodiscovery potential.

RevDate: 2022-10-18
CmpDate: 2022-10-18

He X, Wang X, Fan G, et al (2022)

Metagenomic analysis of viromes in tissues of wild Qinghai vole from the eastern Tibetan Plateau.

Scientific reports, 12(1):17239.

Rodents are natural reservoirs of diverse zoonotic viruses and widely distributed on the Tibetan Plateau. A comprehensive understanding of the virome in local rodent species could provide baseline of viral content and assist in efforts to reduce the risk for future emergence of rodent related zoonotic diseases. A total of 205 tissue and fecal samples from 41 wild Qinghai voles were collected. Metagenomic analyses were performed to outline the characteristics of the viromes, and phylogenetic analyses were used to identify the novel viral genomes. The virome distribution among five tissues (liver, lung, spleen, small intestine with content and feces) was also compared. We identified sequences related to 46 viral families. Novel viral genomes from distinct evolutionary lineages with known viruses were characterized for their genomic and evolutionary characteristics, including Hepatovirus, Hepacivirus, Rotavirus, and Picobirnavirus. Further analyses revealed that the core virome harbored by rodent internal tissues were quite different from the virome found in intestine and fecal samples. These findings provide an overview of the viromes in wild Qinghai voles, which are unique and the most common rodent species in the eastern Tibetan Plateau. A high diversity of viruses is likely present in rodent species in this area.

RevDate: 2022-10-18
CmpDate: 2022-10-18

Zeng W, Gautam A, DH Huson (2022)

DeepToA: an ensemble deep-learning approach to predicting the theater of activity of a microbiome.

Bioinformatics (Oxford, England), 38(20):4670-4676.

MOTIVATION: Metagenomics is the study of microbiomes using DNA sequencing. A microbiome consists of an assemblage of microbes that is associated with a 'theater of activity' (ToA). An important question is, to what degree does the taxonomic and functional content of the former depend on the (details of the) latter? Here, we investigate a related technical question: Given a taxonomic and/or functional profile estimated from metagenomic sequencing data, how to predict the associated ToA? We present a deep-learning approach to this question. We use both taxonomic and functional profiles as input. We apply node2vec to embed hierarchical taxonomic profiles into numerical vectors. We then perform dimension reduction using clustering, to address the sparseness of the taxonomic data and thus make the problem more amenable to deep-learning algorithms. Functional features are combined with textual descriptions of protein families or domains. We present an ensemble deep-learning framework DeepToA for predicting the ToA of amicrobial community, based on taxonomic and functional profiles. We use SHAP (SHapley Additive exPlanations) values to determine which taxonomic and functional features are important for the prediction.

RESULTS: Based on 7560 metagenomic profiles downloaded from MGnify, classified into 10 different theaters of activity, we demonstrate that DeepToA has an accuracy of 98.30%. We show that adding textual information to functional features increases the accuracy.

Our approach is available at http://ab.inf.uni-tuebingen.de/software/deeptoa.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RevDate: 2022-10-18
CmpDate: 2022-10-18

Solari SM, Young RB, Marcelino VR, et al (2022)

expam-high-resolution analysis of metagenomes using distance trees.

Bioinformatics (Oxford, England), 38(20):4814-4816.

SUMMARY: Shotgun metagenomic sequencing provides the capacity to understand microbial community structure and function at unprecedented resolution; however, the current analytical methods are constrained by a focus on taxonomic classifications that may obfuscate functional relationships. Here, we present expam, a tree-based, taxonomy agnostic tool for the identification of biologically relevant clades from shotgun metagenomic sequencing.

expam is an open-source Python application released under the GNU General Public Licence v3.0. expam installation instructions, source code and tutorials can be found at https://github.com/seansolari/expam.

SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RevDate: 2022-10-18
CmpDate: 2022-10-18

Ma W, Drew DA, K Staller (2022)

The Gut Microbiome and Colonic Motility Disorders: A Practical Framework for the Gastroenterologist.

Current gastroenterology reports, 24(10):115-126.

PURPOSE OF REVIEW: Colonic motility disorders may be influenced by the gut microbiota, which plays a role in modulating sensory and motor function. However, existing data are inconsistent, possibly due to complex disease pathophysiology, fluctuation in symptoms, and difficulty characterizing high-resolution taxonomic composition and function of the gut microbiome.

RECENT FINDINGS: Increasingly, human studies have reported associations between gut microbiome features and colonic motility disorders, such as irritable bowel syndrome and constipation. Several microbial metabolites have been identified as regulators of colonic motility in animal models. Modulation of the gut microbiota via dietary intervention, probiotics, and fecal microbiota transplant is a promising avenue for treatment for these diseases. An integration of longitudinal multi-omics data will facilitate further understanding of the causal effects of dysbiosis on disease. Further understanding of the microbiome-driven mechanisms underlying colonic motility disorders may be leveraged to develop personalized, microbiota-based approaches for disease prevention and treatment.

RevDate: 2022-10-16

Pacholak A, Zgoła-Grześkowiak A, E Kaczorek (2022)

Dynamics of microbial communities during biotransformation of nitrofurantoin.

Environmental research pii:S0013-9351(22)01858-8 [Epub ahead of print].

The purpose of this research was to investigate the biodegradation of nitrofurantoin (NFT), a typical nitrofuran antibiotic of potential carcinogenic properties, by two microbial communities derived from distinct environmental niches - mountain stream (NW) and seaport water (SS). The collected samples represent the reserve of the protected area with no human intervention and the contaminated area that concentrates intense human activities. The structure, composition, and diversity of the communities were analyzed at three timepoints during NFT biodegradation. Comamonadaceae (43.2%) and Pseudomonadaceae (19.6%) were the most abundant families in the initial NW sample. The top families in the initial SS sample included Aeromonadaceae (31.4%) and Vibrionaceae (25.3%). The proportion of the most abundant families in both consortia was remarkably reduced in all samples treated with NFT. The biodiversity significantly increased in both consortia treated with NFT suggesting that NFT significantly alters community structure in the aquatic systems. In this study, NFT removal efficiency and transformation products were also studied. The biodegradation rate decreased with the increasing initial NFT concentration. Biodegradation followed similar pathways for both consortia and led to the formation of transformation products: 1-aminohydantoin, semicarbazide (SEM), and hydrazine (HYD). SEM and HYD were detected for the first time as NFT biotransformation products. This study demonstrates that the structure of the microbial community may be directly correlated with the presence of NFT. Increase in biodiversity of the microbial community does not have to be correlated with an increase in functional capacity, such as the ability to biodegradation because higher biodiversity corresponded to lower biodegradation. Our findings provide new insights into the effect of NFT contamination on aquatic microbiomes. The study also increases our understanding of the environmental impact of nitrofuran residues and their biodegradation.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Sun P, Zhu H, Li X, et al (2022)

Comparative Metagenomics and Metabolomes Reveals Abnormal Metabolism Activity Is Associated with Gut Microbiota in Alzheimer's Disease Mice.

International journal of molecular sciences, 23(19):.

A common symptom in Alzheimer's disease (AD) is cognitive decline, of which the potential pathogenesis remains unclear. In order to understand the mechanism of gut microbiota in AD, it is necessary to clarify the relationship between gut microbiota and metabolites. Behavioral tests, pathological examination, metagenomics, and metabolomics were applied to analyze the difference of gut microbiota and metabolome between APPswe/PS1ΔE9 (PAP) mice with cognitive decline and age-matched controls, and their possible correlations. Our results showed that PAP mice and health mice had different structures of the bacterial communities in the gut. The abundances and diversities of the bacterial communities in health mice were higher than in PAP mice by metagenomics analysis. The abundances of Libanicoccus massiliensis, Paraprevotella clara, and Lactobacillus amylovorus were significantly increased in PAP mice, while the abundances of Turicibacter sanguinis, Dubosiella newyorkensis, and Prevotella oris were greatly reduced. Furthermore, PAP mice possessed peculiar metabolic phenotypes in stool, serum, and hippocampus relative to WT mice, as is demonstrated by alterations in neurotransmitters metabolism, lipid metabolism, aromatic amino acids metabolism, energy metabolism, vitamin digestion and absorption, and bile metabolism. Microbiota-host metabolic correlation analysis suggests that abnormal metabolism in stool, serum, and hippocampus of PAP mice may be modulated by the gut microbiota, especially T. sanguinis, D. newyorkensis, and P. oris. Therefore, abnormal metabolism activity is associated with gut microbiota in Alzheimer's disease mice. Our results imply that modifying host metabolism through targeting gut microbiota may be a novel and viable strategy for the prevention and treatment of AD in the future.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Xu P, Chen X, Li K, et al (2022)

Metagenomic Analysis of Microbial Alliances for Efficient Degradation of PHE: Microbial Community Structure and Reconstruction of Metabolic Network.

International journal of environmental research and public health, 19(19):.

Polycyclic aromatic hydrocarbons are a widespread organic pollutant worldwide. In this study, a highly efficient phenanthrene (PHE)-degrading microbial community was enriched from oil extraction soil, which could degrade 500 mg/L PHE within 4 days. Using 16S rRNA sequencing, the dominant bacteria in this community at the phylum level were found to be Proteobacteria, Actinobacteria, and Firmicutes. Metagenomic annotation of genes revealed the metabolic pathways and the contribution of different bacteria to the degradation process. Pseudomonadaceae contributed multiple functional genes in the degradation process. This study revealed the functional genes, metabolic pathways, and microbial interactions of the microbial community, which are expected to provide guidance for practical management.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Zeng Y, JQ Liang (2022)

Nasal Microbiome and Its Interaction with the Host in Childhood Asthma.

Cells, 11(19):.

Childhood asthma is a major chronic non-communicable disease in infants and children, often triggered by respiratory tract infections. The nasal cavity is a reservoir for a broad variety of commensal microbes and potential pathogens associated with respiratory illnesses including asthma. A healthy nasal microenvironment has protective effects against respiratory tract infections. The first microbial colonisation in the nasal region is initiated immediately after birth. Subsequently, colonisation by nasal microbiota during infancy plays important roles in rapidly establishing immune homeostasis and the development and maturation of the immune system. Dysbiosis of microbiota residing in the mucosal surfaces, such as the nasopharynx and guts, triggers immune modulation, severe infection, and exacerbation events. Nasal microbiome dysbiosis is related to the onset of symptomatic infections. Dynamic interactions between viral infections and the nasal microbiota in early life affect the later development of respiratory infections. In this review, we summarise the existing findings related to nasal microbiota colonisation, dynamic variations, and host-microbiome interactions in childhood health and respiratory illness with a particular examination of asthma. We also discuss our current understanding of biases produced by environmental factors and technical concerns, the importance of standardised research methods, and microbiome modification for the prevention or treatment of childhood asthma. This review lays the groundwork for paying attention to an essential but less emphasized topic and improves the understanding of the overall composition, dynamic changes, and influence of the nasal microbiome associated with childhood asthma.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Gounot JS, Chia M, Bertrand D, et al (2022)

Genome-centric analysis of short and long read metagenomes reveals uncharacterized microbiome diversity in Southeast Asians.

Nature communications, 13(1):6044.

Despite extensive efforts to address it, the vastness of uncharacterized 'dark matter' microbial genetic diversity can impact short-read sequencing based metagenomic studies. Population-specific biases in genomic reference databases can further compound this problem. Leveraging advances in hybrid assembly (using short and long reads) and Hi-C technologies in a cross-sectional survey, we deeply characterized 109 gut microbiomes from three ethnicities in Singapore to comprehensively reconstruct 4497 medium and high-quality metagenome assembled genomes, 1708 of which were missing in short-read only analysis and with >28× N50 improvement. Species-level clustering identified 70 (>10% of total) novel gut species out of 685, improved reference genomes for 363 species (53% of total), and discovered 3413 strains unique to these populations. Among the top 10 most abundant gut bacteria in our study, one of the species and >80% of strains were unrepresented in existing databases. Annotation of biosynthetic gene clusters (BGCs) uncovered more than 27,000 BGCs with a large fraction (36-88%) unrepresented in current databases, and with several unique clusters predicted to produce bacteriocins that could significantly alter microbiome community structure. These results reveal significant uncharacterized gut microbial diversity in Southeast Asian populations and highlight the utility of hybrid metagenomic references for bioprospecting and disease-focused studies.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Centurion VB, Campanaro S, Basile A, et al (2022)

Microbiome structure in biofilms from a volcanic island in Maritime Antarctica investigated by genome-centric metagenomics and metatranscriptomics.

Microbiological research, 265:127197.

Antarctica is the coldest and driest continent on Earth, characterized by polyextreme environmental conditions, where species adapted form complex networks of interactions. Microbial communities growing in these harsh environments can form biofilms that help the associated species to survive and thrive. A rich body of knowledge describes environmental biofilm communities; however, most studies have focused on dominant community members rather than functional complexity and metabolic potential. To overcome these limitations, the present study used genome-centric metagenomics to describe two biofilm samples subjected to different temperature collected in Deception Island, Maritime Antarctica. The results unraveled a complex biofilm microbiome represented by 180 metagenome-assembled genomes. The potential metabolic interactions were investigated using metabolic flux balance analysis and revealed that purple bacteria are the community members with the highest correlations with other bacteria. Due to their predicted mixotrophic behavior, they may play a crucial role in the microbiome, likely supporting the heterotrophic species in biofilms. Metatranscriptomics results revealed that the chaperone system and proteins counteracting ROS and toxic compounds have a major role in maintaining bacterial cell homeostasis in sediments of volcanic origin.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Afridi MS, Fakhar A, Kumar A, et al (2022)

Harnessing microbial multitrophic interactions for rhizosphere microbiome engineering.

Microbiological research, 265:127199.

The rhizosphere is a narrow and dynamic region of plant root-soil interfaces, and it's considered one of the most intricate and functionally active ecosystems on the Earth, which boosts plant health and alleviates the impact of biotic and abiotic stresses. Improving the key functions of the microbiome via engineering the rhizosphere microbiome is an emerging tool for improving plant growth, resilience, and soil-borne diseases. Recently, the advent of omics tools, gene-editing techniques, and sequencing technology has allowed us to unravel the entangled webs of plant-microbes interactions, enhancing plant fitness and tolerance to biotic and abiotic challenges. Plants secrete signaling compounds with low molecular weight into the rhizosphere, that engage various species to generate a massive deep complex array. The underlying principle governing the multitrophic interactions of the rhizosphere microbiome is yet unknown, however, some efforts have been made for disease management and agricultural sustainability. This review discussed the intra- and inter- microbe-microbe and microbe-animal interactions and their multifunctional roles in rhizosphere microbiome engineering for plant health and soil-borne disease management. Simultaneously, it investigates the significant impact of immunity utilizing PGPR and cover crop strategy in increasing rhizosphere microbiome functions for plant development and protection using omics techniques. The ecological engineering of rhizosphere plant interactions could be used as a potential alternative technology for plant growth improvement, sustainable disease control management, and increased production of economically significant crops.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Gao J, Zhao X, Hu S, et al (2022)

Gut microbial DL-endopeptidase alleviates Crohn's disease via the NOD2 pathway.

Cell host & microbe, 30(10):1435-1449.e9.

The pattern-recognition receptor NOD2 senses bacterial muropeptides to regulate host immunity and maintain homeostasis. Loss-of-function mutations in NOD2 are associated with Crohn's disease (CD), but how the variations in microbial factors influence NOD2 signaling and host pathology is elusive. We demonstrate that the Firmicutes peptidoglycan remodeling enzyme, DL-endopeptidase, increased the NOD2 ligand level in the gut and impacted colitis outcomes. Metagenomic analyses of global cohorts (n = 857) revealed that DL-endopeptidase gene abundance decreased globally in CD patients and negatively correlated with colitis. Fecal microbiota from CD patients with low DL-endopeptidase activity predisposed mice to colitis. Administering DL-endopeptidase, but not an active site mutant, alleviated colitis via the NOD2 pathway. Therapeutically restoring NOD2 ligands with a DL-endopeptidase-producing Lactobacillus salivarius strain or mifamurtide, a clinical analog of muramyl dipeptide, exerted potent anti-colitis effects. Our study suggests that the depletion of DL-endopeptidase contributes to CD pathogenesis through NOD2 signaling, providing a therapeutically modifiable target.

RevDate: 2022-10-17
CmpDate: 2022-10-17

Sugden S, Holert J, Cardenas E, et al (2022)

Microbiome of the freshwater sponge Ephydatia muelleri shares compositional and functional similarities with those of marine sponges.

The ISME journal, 16(11):2503-2512.

Sponges are known for hosting diverse communities of microbial symbionts, but despite persistent interest in the sponge microbiome, most research has targeted marine sponges; freshwater sponges have been the focus of less than a dozen studies. Here, we used 16 S rRNA gene amplicon sequencing and shotgun metagenomics to characterize the microbiome of the freshwater sponge Ephydatia muelleri and identify potential indicators of sponge-microbe mutualism. Using samples collected from the Sooke, Nanaimo, and Cowichan Rivers on Vancouver Island, British Columbia, we show that the E. muelleri microbiome is distinct from the ambient water and adjacent biofilms and is dominated by Sediminibacterium, Comamonas, and unclassified Rhodospirillales. We also observed phylotype-level differences in sponge microbiome taxonomic composition among different rivers. These differences were not reflected in the ambient water, suggesting that other environmental or host-specific factors may drive the observed geographic variation. Shotgun metagenomes and metagenome-assembled genomes further revealed that freshwater sponge-associated bacteria share many genomic similarities with marine sponge microbiota, including an abundance of defense-related proteins (CRISPR, restriction-modification systems, and transposases) and genes for vitamin B12 production. Overall, our results provide foundational information on the composition and function of freshwater sponge-associated microbes, which represent an important yet underappreciated component of the global sponge microbiome.

RevDate: 2022-10-14
CmpDate: 2022-10-14

Herman MA, Irazoqui JE, Samuel BS, et al (2022)

Editorial: C. elegans host-microbiome interactions: From medical to ecological and evolutionary model.

Frontiers in cellular and infection microbiology, 12:1035545.

RevDate: 2022-10-14
CmpDate: 2022-10-14

Di Gesù CM, Matz LM, Bolding IJ, et al (2022)

Maternal gut microbiota mediate intergenerational effects of high-fat diet on descendant social behavior.

Cell reports, 41(2):111461.

Dysbiosis of the maternal gut microbiome during pregnancy is associated with adverse neurodevelopmental outcomes. We previously showed that maternal high-fat diet (MHFD) in mice induces gut dysbiosis, social dysfunction, and underlying synaptic plasticity deficits in male offspring (F1). Here, we reason that, if HFD-mediated changes in maternal gut microbiota drive offspring social deficits, then MHFD-induced dysbiosis in F1 female MHFD offspring would likewise impair F2 social behavior. Metataxonomic sequencing reveals reduced microbial richness among female F1 MHFD offspring. Despite recovery of microbial richness among MHFD-descendant F2 mice, they display social dysfunction. Post-weaning Limosilactobacillus reuteri treatment increases the abundance of short-chain fatty acid-producing taxa and rescues MHFD-descendant F2 social deficits. L. reuteri exerts a sexually dimorphic impact on gut microbiota configuration, increasing discriminant taxa between female cohorts. Collectively, these results show multigenerational impacts of HFD-induced dysbiosis in the maternal lineage and highlight the potential of maternal microbiome-targeted interventions for neurodevelopmental disorders.

RevDate: 2022-10-12

Espinoza JL, CL Dupont (2022)

VEBA: a modular end-to-end suite for in silico recovery, clustering, and analysis of prokaryotic, microeukaryotic, and viral genomes from metagenomes.

BMC bioinformatics, 23(1):419.

BACKGROUND: With the advent of metagenomics, the importance of microorganisms and how their interactions are relevant to ecosystem resilience, sustainability, and human health has become evident. Cataloging and preserving biodiversity is paramount not only for the Earth's natural systems but also for discovering solutions to challenges that we face as a growing civilization. Metagenomics pertains to the in silico study of all microorganisms within an ecological community in situ, however, many software suites recover only prokaryotes and have limited to no support for viruses and eukaryotes.

RESULTS: In this study, we introduce the Viral Eukaryotic Bacterial Archaeal (VEBA) open-source software suite developed to recover genomes from all domains. To our knowledge, VEBA is the first end-to-end metagenomics suite that can directly recover, quality assess, and classify prokaryotic, eukaryotic, and viral genomes from metagenomes. VEBA implements a novel iterative binning procedure and hybrid sample-specific/multi-sample framework that yields more genomes than any existing methodology alone. VEBA includes a consensus microeukaryotic database containing proteins from existing databases to optimize microeukaryotic gene modeling and taxonomic classification. VEBA also provides a unique clustering-based dereplication strategy allowing for sample-specific genomes and genes to be directly compared across non-overlapping biological samples. Finally, VEBA is the only pipeline that automates the detection of candidate phyla radiation bacteria and implements the appropriate genome quality assessments. VEBA's capabilities are demonstrated by reanalyzing 3 existing public datasets which recovered a total of 948 MAGs (458 prokaryotic, 8 eukaryotic, and 482 viral) including several uncharacterized organisms and organisms with no public genome representatives.

CONCLUSIONS: The VEBA software suite allows for the in silico recovery of microorganisms from all domains of life by integrating cutting edge algorithms in novel ways. VEBA fully integrates both end-to-end and task-specific metagenomic analysis in a modular architecture that minimizes dependencies and maximizes productivity. The contributions of VEBA to the metagenomics community includes seamless end-to-end metagenomics analysis but also provides users with the flexibility to perform specific analytical tasks. VEBA allows for the automation of several metagenomics steps and shows that new information can be recovered from existing datasets.

RevDate: 2022-10-13
CmpDate: 2022-10-13

Shareefdeen H, C Hill (2022)

The gut virome in health and disease: new insights and associations.

Current opinion in gastroenterology, 38(6):549-554.

PURPOSE OF REVIEW: Recent years have seen great strides made in the field of viral metagenomics. Many studies have reported alterations in the virome in different disease states. The vast majority of the human intestinal virome consists of bacteriophages, viruses that infect bacteria. The dynamic relationship between gut bacterial populations and bacteriophages is influenced by environmental factors that also impact host health and disease. In this review, we focus on studies highlighting the dynamics of the gut virome and fluctuations associated with disease states.

RECENT FINDINGS: Novel correlations have been identified between the human gut virome and diseases such as obesity, necrotizing enterocolitis and severe acute respiratory syndrome coronavirus 2 infection. Further associations between the virome and cognition, diet and geography highlight the complexity of factors that can influence the dynamic relationship between gut bacteria, bacteriophages and health.

SUMMARY: Here, we highlight some novel associations between the virome and health that will be the foundation for future studies in this field. The future development of microbiome-based interventions, identification of biomarkers, and novel therapeutics will require a thorough understanding of the gut virome and its dynamics.

RevDate: 2022-10-13
CmpDate: 2022-10-13

Zheng M, Shao S, Chen Y, et al (2022)

Metagenomics analysis of microbial community distribution in large-scale and step-by-step purification system of swine wastewater.

Environmental pollution (Barking, Essex : 1987), 313:120137.

Biological treatment is one of the most widely used methods to treat swine wastewater in wastewater treatment plants. The microbial community plays an important role in the swine slurry treatment system. However, limited information is available regarding the correlation between pollutant concentration and dominant microbial community in swine wastewater. This work aimed to study the profiling of microbial communities and their abundance in the 40 M3/day large-scale and step-by-step treatment pools of swine wastewater. Metagenome sequencing was applied to study the changes of microbial community structure in biochemical reaction pools. The results showed that in the heavily polluted pools, it was mainly Proteobacteria, Cyanobacteria, Chlorella and other strains that could tolerate high concentration of ammonia nitrogen to remove nitrogen and absorb chemical oxygen demand (COD). In the moderately polluted pools, Nitrospirae, Actinobacteria and other strains further cooperated to purify swine wastewater. In the later stage, the emergence of Brachionus indicated the reduction of water pollution. The dominant microbes and their abundance changed with the purification of swine wastewater in different stages. Moreover, the dominant microflora of swine wastewater treatment pools at all levels reflected little difference in phylum classification level, while in genus classification level, the dominant microflora manifested great difference. Findings demonstrated that the microorganisms maintained ecological balance and absorbed the nutrients in the swine wastewater treatment pools, so as to play the role of purifying sewage. Therefore, the stepwise purification of swine wastewater can be realized by adding bacteria and microalgae of different genera.

RevDate: 2022-10-13
CmpDate: 2022-10-13

Yang H, Huang Y, Li K, et al (2022)

Lignocellulosic depolymerization induced by ionic liquids regulating composting habitats based on metagenomics analysis.

Environmental science and pollution research international, 29(50):76298-76309.

The application of ionic liquids with sawdust and fresh dairy manure was studied in composting. The degradation of organic matter (OM), dissolved organic matter (DOM), and lignocellulose was analyzed. The DOM decreased by 14.25 mg/g and 11.11 mg/g in experimental group (ILs) and control group (CK), respectively. OM decreased by 7.32% (CK) and 8.91% (ILs), respectively. The degradation rates of hemicellulose, lignin, and cellulose in ILs (56.62%, 42.01%, and 23.97%) were higher than in CK (38.39%, 39.82%, and 16.04%). Microbial community and carbohydrate-active enzymes (CAZymes) were analyzed based on metagenomics. Metagenomic analysis results showed that ionic liquids enriched Actinobacteria and Proteobacteria in composting. Compared with CK, the total abundance values of GH11, GH6, AA6, and AA3_2 in ILs increased by 13.98%, 10.12%, 11.21%, and 13.68%, respectively. Ionic liquids can improve the lignocellulosic degradation by regulating the environmental physicochemical parameters (temperature, pH, C/N) to promote the growth of Actinobacteria and Proteobacteria and carbohydrate-active enzymes (CAZymes) abundance. Therefore, ionic liquids are a promising additive in lignocellulosic waste composting.

RevDate: 2022-10-12
CmpDate: 2022-10-12

Gül F, Karadayı S, Yurdabakan Z, et al (2022)

Investigating changes in salivary microbiota due to dental treatment: A metagenomic analysis study for forensic purposes.

Forensic science international, 340:111447.

The advent of next generation sequencing techniques as well as the existing traditional culture methods has enabled metagenomic studies on the usability of microbiomes for the forensic identification of individuals to gain momentum. However, before the utilization of microbiomes as a potential technique for real forensic case resolutions, it is necessary to understand the stability of the microbiota compositions in an individual's biological samples and the factors responsible for their variations. In the present study, we compared the microbiota compositions present in the saliva of individuals with active dental caries before and after treatment from a forensic and clinical perspective using an approach based on the sequencing of all the variable regions (V1-V9) of the bacterial 16 S rRNA gene. For this purpose, 10 individuals were included in the study comprising of 8 individuals between the ages of 18-50 years with at least 3 deep dentin caries as patients and 2 healthy individuals without any dental or gingival diseases as controls. Saliva samples were collected from the patients at two timepoints, before and after treatment, as well as from the healthy individuals (before and after control) at an interval of 1 month. The collected 20 saliva samples were subjected to metagenomic analysis using the MinION device, which was developed by Oxford Nanopore Technologies (ONT Oxford, UK). Bioinformatic analyses were performed on the obtained data and the results were evaluated using statistical comparison methods and alpha/beta diversity analyses within the scope of the study objective. On evaluation using the distance metrics, it was observed that the microbial compositions in the saliva of individuals with active caries remained relatively stable after treatment. However, the relative abundance levels of bacteria of 28 genera and species showed statistically significant differences before and after treatment (p < 0.05). As a result, although the composition of salivary microbiome remained relatively stable after caries treatment, there were significant changes in many types of bacteria, especially at the species level, between the BT and AT samples. Our results provide a framework for further forensic and clinical investigations regarding the factors that affect human salivary microbiome diversity.

RevDate: 2022-10-11
CmpDate: 2022-10-11

Shifera AS, Pockrandt C, Rincon N, et al (2021)

Identification of microbial agents in tissue specimens of ocular and periocular sarcoidosis using a metagenomics approach.

F1000Research, 10:820.

Background: Metagenomic sequencing has the potential to identify a wide range of pathogens in human tissue samples. Sarcoidosis is a complex disorder whose etiology remains unknown and for which a variety of infectious causes have been hypothesized. We sought to conduct metagenomic sequencing on cases of ocular and periocular sarcoidosis, none of them with previously identified infectious causes. Methods: Archival tissue specimens of 16 subjects with biopsies of ocular and periocular tissues that were positive for non-caseating granulomas were used as cases. Four archival tissue specimens that did not demonstrate non-caseating granulomas were also included as controls. Genomic DNA was extracted from tissue sections. DNA libraries were generated from the extracted genomic DNA and the libraries underwent next-generation sequencing. Results: We generated between 4.8 and 20.7 million reads for each of the 16 cases plus four control samples. For eight of the cases, we identified microbial pathogens that were present well above the background, with one potential pathogen identified for seven of the cases and two possible pathogens for one of the cases. Five of the eight cases were associated with bacteria (Campylobacter concisus, Neisseria elongata, Streptococcus salivarius, Pseudopropionibacterium propionicum, and Paracoccus yeei), two cases with fungi (Exophiala oligosperma, Lomentospora prolificans and Aspergillus versicolor) and one case with a virus (Mupapillomavirus 1). Interestingly, four of the five bacterial species are also part of the human oral microbiome. Conclusions: Using a metagenomic sequencing we identified possible infectious causes in half of the ocular and periocular sarcoidosis cases analyzed. Our findings support the proposition that sarcoidosis could be an etiologically heterogenous disease. Because these are previously banked samples, direct follow-up in the respective patients is impossible, but these results suggest that sequencing may be a valuable tool in better understanding the etiopathogenesis of sarcoidosis and in diagnosing and treating this disease.

RevDate: 2022-10-11
CmpDate: 2022-10-11

Zhao L, Wang C, Peng S, et al (2022)

Pivotal interplays between fecal metabolome and gut microbiome reveal functional signatures in cerebral ischemic stroke.

Journal of translational medicine, 20(1):459.

BACKGROUND: Integrative analysis approaches of metagenomics and metabolomics have been widely developed to understand the association between disease and the gut microbiome. However, the different profiling patterns of different metabolic samples in the association analysis make it a matter of concern which type of sample is the most closely associated with gut microbes and disease. To address this lack of knowledge, we investigated the association between the gut microbiome and metabolomic profiles of stool, urine, and plasma samples from ischemic stroke patients and healthy subjects.

METHODS: We performed metagenomic sequencing (feces) and untargeted metabolomics analysis (feces, plasma, and urine) from ischemic stroke patients and healthy volunteers. Differential analyses were conducted to find key differential microbiota and metabolites for ischemic stroke. Meanwhile, Spearman's rank correlation and linear regression analyses were used to study the association between microbiota and metabolites of different metabolic mixtures.

RESULTS: Untargeted metabolomics analysis shows that feces had the most abundant features and identified metabolites, followed by urine and plasma. Feces had the highest number of differential metabolites between ischemic stroke patients and the healthy group. Based on the association analysis between metagenomics and metabolomics of fecal, urine, and plasma, fecal metabolome showed the strongest association with the gut microbiome. There are 1073, 191, and 81 statistically significant pairs (P < 0.05) in the correlation analysis for fecal, urine, and plasma metabolome. Fecal metabolites explained the variance of alpha-diversity of the gut microbiome up to 31.1%, while urine and plasma metabolites only explained the variance of alpha-diversity up to 13.5% and 10.6%. Meanwhile, there were more significant differential metabolites in feces than urine and plasma associated with the stroke marker bacteria.

CONCLUSIONS: The systematic association analysis between gut microbiome and metabolomics reveals that fecal metabolites show the strongest association with the gut microbiome, followed by urine and plasma. The findings would promote the association study between the gut microbiome and fecal metabolome to explore key factors that are associated with diseases. We also provide a user-friendly web server and a R package to facilitate researchers to conduct the association analysis of gut microbiome and metabolomics.

RevDate: 2022-10-11
CmpDate: 2022-10-07

Palmnäs-Bédard MSA, Costabile G, Vetrani C, et al (2022)

The human gut microbiota and glucose metabolism: a scoping review of key bacteria and the potential role of SCFAs.

The American journal of clinical nutrition, 116(4):862-874.

The gut microbiota plays a fundamental role in human nutrition and metabolism and may have direct implications for type 2 diabetes and associated preconditions. An improved understanding of relations between human gut microbiota and glucose metabolism could lead to novel opportunities for type 2 diabetes prevention, but human observational studies reporting on such findings have not been extensively reviewed. Here, we review the literature on associations between gut microbiota and markers and stages of glucose dysregulation and insulin resistance in healthy adults and in adults with metabolic disease and risk factors. We present the current evidence for identified key bacteria and their potential roles in glucose metabolism independent of overweight, obesity, and metabolic drugs. We provide support for SCFAs mediating such effects and discuss the role of diet, as well as metabolites derived from diet and gut microbiota interactions. From 5983 initially identified PubMed records, 45 original studies were eligible and reviewed. α Diversity and 45 bacterial taxa were associated with selected outcomes. Six taxa were most frequently associated with glucose metabolism: Akkermansia muciniphila, Bifidobacterium longum, Clostridium leptum group, Faecalibacterium prausnitzii, and Faecalibacterium (inversely associated) and Dorea (directly associated). For Dorea and A. muciniphila, associations were independent of metabolic drugs and body measures. For A. muciniphila and F. prausnitzii, limited evidence supported SCFA mediation of potential effects on glucose metabolism. We conclude that observational studies applying metagenomics sequencing to identify species-level relations are warranted, as are studies accounting for confounding factors and investigating SCFA and postprandial glucose metabolism. Such advances in the field will, together with mechanistic and prospective studies and investigations into diet-gut microbiota interactions, have the potential to bring critical insight into roles of gut microbiota and microbial metabolites in human glucose metabolism and to contribute toward the development of novel prevention strategies for type 2 diabetes, including precision nutrition.

RevDate: 2022-10-11
CmpDate: 2022-10-11

Natola L, Seneviratne SS, D Irwin (2022)

Population genomics of an emergent tri-species hybrid zone.

Molecular ecology, 31(20):5356-5367.

Isolating barriers that drive speciation are commonly studied in the context of two-species hybrid zones. There is, however, evidence that more complex introgressive relationships are common in nature. Here, we use field observations and genomic analysis, including the sequencing and assembly of a novel reference genome, to study an emergent hybrid zone involving two colliding hybrid zones of three woodpecker species: red-breasted, red-naped, and yellow-bellied sapsuckers (Sphyrapicus ruber, S. nuchalis, and S. varius). Surveys of the area surrounding Prince George, British Columbia, Canada, show that all three species are sympatric, and Genotyping-by-Sequencing identifies hybrids from each species pair and birds with ancestry from all three species. Observations of phenotypes and genotypes of mated pairs provide evidence for assortative mating, though there is some heterospecific pairing. Hybridization is more extensive in this tri-species hybrid zone than in two di-species hybrid zones. However, there is no evidence of a hybrid swarm and admixture is constrained to contact zones, so we classify this region as a tension zone and invoke selection against hybrids as a likely mechanism maintaining species boundaries. Analysis of sapsucker age classes does not show disadvantages in hybrid survival to adulthood, so we speculate the selection upholding the tension zone may involve hybrid fecundity. Gene flow among all sapsuckers in di-species hybrid zones suggests introgression probably occurred before the formation of this tri-species hybrid zone, and might result from bridge hybridization, vagrancies, or other three-species interactions.

RevDate: 2022-10-06
CmpDate: 2022-10-06

Kelly JB, Carlson DE, Low JS, et al (2022)

Novel trends of genome evolution in highly complex tropical sponge microbiomes.

Microbiome, 10(1):164.

BACKGROUND: Tropical members of the sponge genus Ircinia possess highly complex microbiomes that perform a broad spectrum of chemical processes that influence host fitness. Despite the pervasive role of microbiomes in Ircinia biology, it is still unknown how they remain in stable association across tropical species. To address this question, we performed a comparative analysis of the microbiomes of 11 Ircinia species using whole-metagenomic shotgun sequencing data to investigate three aspects of bacterial symbiont genomes-the redundancy in metabolic pathways across taxa, the evolution of genes involved in pathogenesis, and the nature of selection acting on genes relevant to secondary metabolism.

RESULTS: A total of 424 new, high-quality bacterial metagenome-assembled genomes (MAGs) were produced for 10 Caribbean Ircinia species, which were evaluated alongside 113 publicly available MAGs sourced from the Pacific species Ircinia ramosa. Evidence of redundancy was discovered in that the core genes of several primary metabolic pathways could be found in the genomes of multiple bacterial taxa. Across hosts, the metagenomes were depleted in genes relevant to pathogenicity and enriched in eukaryotic-like proteins (ELPs) that likely mimic the hosts' molecular patterning. Finally, clusters of steroid biosynthesis genes (CSGs), which appear to be under purifying selection and undergo horizontal gene transfer, were found to be a defining feature of Ircinia metagenomes.

CONCLUSIONS: These results illustrate patterns of genome evolution within highly complex microbiomes that illuminate how associations with hosts are maintained. The metabolic redundancy within the microbiomes could help buffer the hosts from changes in the ambient chemical and physical regimes and from fluctuations in the population sizes of the individual microbial strains that make up the microbiome. Additionally, the enrichment of ELPs and depletion of LPS and cellular motility genes provide a model for how alternative strategies to virulence can evolve in microbiomes undergoing mixed-mode transmission that do not ultimately result in higher levels of damage (i.e., pathogenicity) to the host. Our last set of results provides evidence that sterol biosynthesis in Ircinia-associated bacteria is widespread and that these molecules are important for the survival of bacteria in highly complex Ircinia microbiomes. Video Abstract.

RevDate: 2022-10-05
CmpDate: 2022-10-05

Yang Z, Chen Z, Lin X, et al (2022)

Rural environment reduces allergic inflammation by modulating the gut microbiota.

Gut microbes, 14(1):2125733.

Rural environments and microbiota are linked to a reduction in the prevalence of allergies. However, the mechanism underlying the reduced allergies modulated by rural residency is unclear. Here, we assessed gut bacterial composition and metagenomics in urban and rural children in the EuroPrevall-INCO cohort. Airborne dusts, including mattress and rural henhouse dusts, were profiled for bacterial and fungal composition by amplicon sequencing. Mice were repeatedly exposed to intranasal dust extracts and evaluated for their effects on ovalbumin (OVA)-induced allergic airway inflammation, and gut microbiota restoration was validated by fecal microbiota transplant (FMT) from dust-exposed donor mice. We found that rural children had fewer allergies and unique gut microbiota with fewer Bacteroides and more Prevotella. Indoor dusts in rural environments harbored higher endotoxin level and diversity of bacteria and fungi, whereas indoor urban dusts were enriched with Aspergillus and contained elevated pathogenic bacteria. Intranasal administration of rural dusts before OVA sensitization reduced respiratory eosinophils and blood IgE level in mice and also led to a recovery of gut bacterial diversity and Ruminiclostridium in the mouse model. FMT restored the protective effect by reducing OVA-induced lung eosinophils in recipient mice. Together, these results support a cause-effect relationship between exposure to dust microbiota and allergy susceptibility in children and mice. Specifically, rural environmental exposure modulated the gut microbiota, which was essential in reducing allergy in children from Southern China. Our findings support the notion that the modulation of gut microbiota by exposure to rural indoor dust may improve allergy prevention.

RevDate: 2022-10-05
CmpDate: 2022-10-05

Ma S, Shungin D, Mallick H, et al (2022)

Population structure discovery in meta-analyzed microbial communities and inflammatory bowel disease using MMUPHin.

Genome biology, 23(1):208.

Microbiome studies of inflammatory bowel diseases (IBD) have achieved a scale for meta-analysis of dysbioses among populations. To enable microbial community meta-analyses generally, we develop MMUPHin for normalization, statistical meta-analysis, and population structure discovery using microbial taxonomic and functional profiles. Applying it to ten IBD cohorts, we identify consistent associations, including novel taxa such as Acinetobacter and Turicibacter, and additional exposure and interaction effects. A single gradient of dysbiosis severity is favored over discrete types to summarize IBD microbiome population structure. These results provide a benchmark for characterization of IBD and a framework for meta-analysis of any microbial communities.

RevDate: 2022-10-05
CmpDate: 2022-10-05

Perez-Marron J, Sanders C, Gomez E, et al (2022)

Community and shotgun metagenomic analysis of Alligator mississippiensis oral cavity and GI tracts reveal complex ecosystems and potential reservoirs of antibiotic resistance.

Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, 274:111319.

We report here the community structure and functional analysis of the microbiome of the Alligator mississippiensis GI tract from the oral cavity through the entirety of the digestive tract. Although many vertebrate microbiomes have been studied in recent years, the archosaur microbiome has only been given cursory attention. In the oral cavity we used amplicon-based community analysis to examine the structure of the oral microbiome during alligator development. We found a community that diversified over time and showed many of the hallmarks we would expect of a stable oral community. This is a bit surprising given the rapid turnover of alligator teeth but suggests that the stable gumline microbes are able to rapidly colonize the emerging teeth. As we move down the digestive tract, we were able to use both long and short read sequencing approaches to evaluate the community using a shotgun metagenomics approach. Long read sequencing was applied to samples from the stomach/duodenum, and the colorectal region, revealing a fairly uniform and low complexity community made up primarily of proteobacteria at the top of the gut and much more diversity in the colon. We used deep short read sequencing to further interrogate this colorectal community. The two sequencing approaches were concordant with respect to community structure but substantially more detail was available in the short read data, in spite of high levels of host DNA contamination. Using both approaches we were able to show that the colorectal community is a potential reservoir for antibiotic resistance, human pathogens such as Clostridiodes difficile and a possible source of novel antimicrobials or other useful secondary metabolites.

RevDate: 2022-10-05
CmpDate: 2022-10-05

Wang Y, Zhang Y, Lane NE, et al (2022)

Population-based metagenomics analysis reveals altered gut microbiome in sarcopenia: data from the Xiangya Sarcopenia Study.

Journal of cachexia, sarcopenia and muscle, 13(5):2340-2351.

BACKGROUND: Several studies have examined gut microbiota and sarcopenia using 16S ribosomal RNA amplicon sequencing; however, this technique may not be able to identify altered specific species and functional capacities of the microbes. We performed shotgun metagenomic sequencing to compare the gut microbiome composition and function between individuals with and without sarcopenia.

METHODS: Participants were from a community-based observational study conducted among the residents of rural areas in China. Appendicular skeletal muscle mass was assessed using direct segmental multi-frequency bioelectrical impedance and grip strength using a Jamar Hydraulic Hand dynamometer. Physical performance was evaluated using the Short Physical Performance Battery, 5-time chair stand test and gait speed with the 6 m walk test. Sarcopenia and its severity were diagnosed according to the Asian Working Group for Sarcopenia 2019 algorithm. The gut microbiome was profiled by shotgun metagenomic sequencing to determine the microbial composition and function. A gut microbiota-based model for classification of sarcopenia was constructed using the random forest model, and its performance was assessed using the area under receiver-operating characteristic curve (AUC).

RESULTS: The study sample included 1417 participants (women: 58.9%; mean age: 63.3 years; sarcopenia prevalence: 10.0%). β-diversity indicated by Bray-Curtis distance (genetic level: P = 0.004; taxonomic level of species: P = 0.020), but not α-diversity indicated by Shannon index (genetic level: P = 0.962; taxonomic level of species: P = 0.922), was significantly associated with prevalent sarcopenia. After adjusting for potential confounders, participants with sarcopenia had higher relative abundance of Desulfovibrio piger (P = 0.003, Q = 0.090), Clostridium symbiosum (P < 0.001, Q = 0.035), Hungatella effluvii (P = 0.003, Q = 0.090), Bacteroides fluxus (P = 0.002, Q = 0.089), Absiella innocuum (P = 0.002, Q = 0.072), Coprobacter secundus (P = 0.002, Q = 0.085) and Clostridium citroniae (P = 0.001, Q = 0.060) than those without sarcopenia. The relative abundance of six species (Desulfovibrio piger, Clostridium symbiosum, Hungatella effluvii, Bacteroides fluxus, Absiella innocuum, and Clostridium citroniae) was also positively associated with sarcopenia severity. A differential species-based model was constructed to separate participants with sarcopenia from controls. The value of the AUC was 0.852, suggesting that model has a decent discriminative performance. Desulfovibrio piger ranked the highest in this model. Functional annotation analysis revealed that the phenylalanine, tyrosine, and tryptophan biosynthesis were depleted (P = 0.006, Q = 0.071), while alpha-Linolenic acid metabolism (P = 0.008, Q = 0.094), furfural degradation (P = 0.001, Q = 0.029) and staurosporine biosynthesis (P = 0.006, Q = 0.072) were enriched in participants with sarcopenia. Desulfovibrio piger was significantly associated with staurosporine biosynthesis (P < 0.001).

CONCLUSIONS: This large population-based observational study provided empirical evidence that alterations in the gut microbiome composition and function were observed among individuals with sarcopenia.

RevDate: 2022-10-05
CmpDate: 2022-10-05

Tham KC, Lefferdink R, Duan K, et al (2022)

Distinct skin microbiome community structures in congenital ichthyosis.

The British journal of dermatology, 187(4):557-570.

BACKGROUND: The ichthyoses are rare genetic keratinizing disorders that share the characteristics of an impaired epidermal barrier and increased risk of microbial infections. Although ichthyotic diseases share a T helper (Th) 17 cell immune signature, including increased expression of antimicrobial peptides, the skin microbiota of ichthyoses is virtually unexplored.

OBJECTIVES: To analyse the metagenome profile of skin microbiome for major congenital ichthyosis subtypes.

METHODS: Body site-matched skin surface samples were collected from the scalp, upper arm and upper buttocks of 16 healthy control participants and 22 adult patients with congenital forms of ichthyosis for whole metagenomics sequencing analysis.

RESULTS: Taxonomic profiling showed significant shifts in bacteria and fungi abundance and sporadic viral increases across ichthyosis subtypes. Cutibacterium acnes and Malassezia were significantly reduced across body sites, consistent with skin barrier disruption and depletion of lipids. Microbial richness was reduced, with specific increases in Staphylococcus and Corynebacterium genera, as well as shifts in fungal species, including Malassezia. Malassezia globosa was reduced at all body sites, whereas M. sympodialis was reduced in the ichthyotic upper arm and upper buttocks. Malassezia slooffiae, by contrast, was strikingly increased at all body sites in participants with congenital ichthyosiform erythroderma (CIE) and lamellar ichthyosis (LI). A previously undescribed Trichophyton species was also detected as sporadically colonizing the skin of patients with CIE, LI and epidermolytic ichthyosis subtypes.

CONCLUSIONS: The ichthyosis skin microbiome is significantly altered from healthy skin with specific changes predominating among ichthyosis subtypes. Skewing towards the Th17 pathway may represent a response to the altered microbial colonization in ichthyosis. What is already known about this topic? The skin microbiome of congenital ichthyoses is largely unexplored. Microbes play an important role in pathogenesis, as infections are common. The relative abundances of staphylococci and corynebacteria is increased in the cutaneous microbiome of patients with Netherton syndrome, but extension of these abundances to all congenital ichthyoses is unexplored. What does this study add? A common skin microbiome signature was observed across congenital ichthyoses. Distinct microbiome features were associated with ichthyosis subtypes. Changes in microbiome may contribute to T helper 17 cell immune polarization. What is the translational message? These data provide the basis for comparison of the microbiome with lipidomic and transcriptomic alterations in these forms of ichthyosis and consideration of correcting the dysbiosis as a therapeutic intervention.

RevDate: 2022-10-04
CmpDate: 2022-10-04

Santiago-Rodriguez TM, EB Hollister (2022)

Unraveling the viral dark matter through viral metagenomics.

Frontiers in immunology, 13:1005107.

Viruses are part of the microbiome and have essential roles in immunology, evolution, biogeochemical cycles, health, and disease progression. Viruses influence a wide variety of systems and processes, and the continued discovery of novel viruses is anticipated to reveal new mechanisms influencing the biology of diverse environments. While the identity and roles of viruses continue to be discovered and understood through viral metagenomics, most of the sequences in virome datasets cannot be attributed to known viruses or may be only distantly related to species already described in public sequence databases, at best. Such viruses are known as the viral dark matter. Ongoing discoveries from the viral dark matter have provided insights into novel viruses from a variety of environments, as well as their potential in immunological processes, virus evolution, health, disease, therapeutics, and surveillance. Increased understanding of the viral dark matter will continue with a combination of cultivation, microscopy, sequencing, and bioinformatic efforts, which are discussed in the present review.

RevDate: 2022-10-04
CmpDate: 2022-10-04

Narunsky-Haziza L, Sepich-Poore GD, Livyatan I, et al (2022)

Pan-cancer analyses reveal cancer-type-specific fungal ecologies and bacteriome interactions.

Cell, 185(20):3789-3806.e17.

Cancer-microbe associations have been explored for centuries, but cancer-associated fungi have rarely been examined. Here, we comprehensively characterize the cancer mycobiome within 17,401 patient tissue, blood, and plasma samples across 35 cancer types in four independent cohorts. We report fungal DNA and cells at low abundances across many major human cancers, with differences in community compositions that differ among cancer types, even when accounting for technical background. Fungal histological staining of tissue microarrays supported intratumoral presence and frequent spatial association with cancer cells and macrophages. Comparing intratumoral fungal communities with matched bacteriomes and immunomes revealed co-occurring bi-domain ecologies, often with permissive, rather than competitive, microenvironments and distinct immune responses. Clinically focused assessments suggested prognostic and diagnostic capacities of the tissue and plasma mycobiomes, even in stage I cancers, and synergistic predictive performance with bacteriomes.

RevDate: 2022-10-04
CmpDate: 2022-10-04

Jung TH, Hwang HJ, KS Han (2022)

Correlation of attention deficit hyperactivity disorder with gut microbiota according to the dietary intake of Korean elementary school students.

PloS one, 17(9):e0275520.

We investigated the impact of dietary patterns on the gut microbiota and concentration of short-chain fatty acids in the feces of Korean elementary school students. The dietary intake and ADHD assessment of 40 Korean elementary school students were analyzed using a dish-based semi-quantitative food frequency questionnaire. Analysis of gut microbiota and short-chain fatty acids composition were performed using the real-time polymerase chain reaction, metagenomics, and gas chromatography methods. The dietary patterns of participants were divided into four groups: healthy, processed food, fish and shellfish, and meat. The participants were also divided into two groups according to their ADHD scores: 0-30, control group; over 30, ADHD group. The ADHD score of the processed food group was significantly higher than that of the healthy group. The processed food and ADHD groups showed significantly higher abundance of harmful bacteria, such as the Enterobacter, Escherichia coli, and Clostridium strains, and markedly lower abundance of beneficial bacteria, such as the Bifidobacterium and Ruminococcus strains, than the control group. The heat maps of metagenomics indicated that each group was separated into distinct clusters, and the processed food and ADHD groups showed significantly lower α-diversity of gut microbiota than the control group. In these groups, the concentration of acetate or butyrate in the feces was significantly lower than that in the control group. These results may indicate that imbalanced diets can disturb the colonic microbial balance and are likely to become a potential risk factor for the prevalence of ADHD.

RevDate: 2022-10-04
CmpDate: 2022-10-04

Medina V, Rosso BE, Soria M, et al (2022)

Feeding on soybean crops changed gut bacteria diversity of the southern green stinkbug (Nezara viridula) and reduced negative effects of some associated bacteria.

Pest management science, 78(11):4608-4617.

BACKGROUND: The southern green stinkbug (Nezara viridula) is a mayor pest of soybean. However, the mechanism underlying stinkbug resistance to soybean defenses is yet ignored. Although gut bacteria could play an essential role in tolerating plant defenses, most studies testing questions related to insect-plant-bacteria interactions have been performed in laboratory condition. Here we performed experiments in laboratory and field conditions with N. viridula and its gut bacteria, studying gut lipid peroxidaxion levels and cysteine activity in infected and unifected nymphs, testing the hypothesis that feeding on field-grown soybean decreases bacterial abundance in stinkbugs.

RESULTS: Gut bacterial abundance and infection ratio were higher in N. viridula adults reared in laboratory than in those collected from soybean crops, suggesting that stinkbugs in field conditions may modulate gut bacterial colonization. Manipulating gut microbiota by infecting stinkbugs with Yokenella sp. showed that these bacteria abundance decreased in field conditions, and negatively affected stinkbugs performance and were more aggressive in laboratory rearing than in field conditions. Infected nymphs that fed on soybean pods had lower mortality, higher mass and shorter development period than those reared in the laboratory, and suggested that field conditions helped nymphs to recover from Yokenella sp. infection, despite of increased lipid peroxidation and decreased cysteine proteases activity in nymphs' guts.

CONCLUSIONS: Our results demonstrated that feeding on field-grown soybean reduced bacterial abundance and infection in guts of N. viridula and highlighted the importance to test functional activities or pathogenicity of microbes under realistic field conditions prior to establish conclusions on three trophic interactions. © 2022 Society of Chemical Industry.

RevDate: 2022-10-03
CmpDate: 2022-10-03

Laue HE, Karagas MR, Coker MO, et al (2022)

Sex-specific relationships of the infant microbiome and early-childhood behavioral outcomes.

Pediatric research, 92(2):580-591.

BACKGROUND: A link between the gut microbiome and behavior is hypothesized, but most previous studies are cross-sectional or in animal models. The modifying role of host sex is poorly characterized. We aimed to identify sex-specific prospective associations between the early-life gut microbiome and preschool-age neurobehavior.

METHODS: In a prospective cohort, gut microbiome diversity and taxa were estimated with 16S rRNA sequencing at 6 weeks, 1 year, and 2 years. Species and gene pathways were inferred from metagenomic sequencing at 6 weeks and 1 year. When subjects were 3 years old, parents completed the Behavioral Assessment System for Children, second edition (BASC-2). A total of 260 children contributed 523 16S rRNA and 234 metagenomics samples to analysis. Models adjusted for sociodemographic characteristics.

RESULTS: Higher diversity at 6 weeks was associated with better internalizing problems among boys, but not girls [βBoys = -1.86 points/SD Shannon diversity; 95% CI (-3.29, -0.42), pBoys = 0.01, βGirls = 0.22 (-1.43, 1.87), pGirls = 0.8, pinteraction = 0.06]. Among other taxa-specific associations, Bifidobacterium at 6 weeks was associated with Adaptive Skills scores in a sex-specific manner. We observed relationships between functional features and BASC-2 scores, including vitamin B6 biosynthesis pathways and better Depression scores.

CONCLUSIONS: This study advances our understanding of microbe-host interactions with implications for childhood behavioral health.

IMPACT: This is one of the first studies to examine the early-life microbiome and neurobehavior, and the first to examine prospective sex-specific associations. Infant and early-childhood microbiomes relate to neurobehavior including anxiety, depression, hyperactivity, and social behaviors in a time- and sex-specific manner. Our findings suggest future studies should evaluate whether host sex impacts the relationship between the gut microbiome and behavioral health outcomes.

RevDate: 2022-10-01

Tian J, Hou X, Ge M, et al (2022)

The diversity and evolutionary relationships of ticks and tick-borne bacteria collected in China.

Parasites & vectors, 15(1):352.

BACKGROUND: Ticks (order Ixodida) are ectoparasites, vectors and reservoirs of many infectious agents affecting humans and domestic animals. However, the lack of information on tick genomic diversity leaves significant gaps in the understanding of the evolution of ticks and associated bacteria.

RESULTS: We collected > 20,000 contemporary and historical (up to 60 years of preservation) tick samples representing a wide range of tick biodiversity across diverse geographic regions in China. Metagenomic sequencing was performed on individual ticks to obtain the complete or near-complete mitochondrial (mt) genome sequences from 46 tick species, among which mitochondrial genomes of 23 species were recovered for the first time. These new mt genomes data greatly expanded the diversity of many tick groups and revealed five cryptic species. Utilizing the same metagenomic sequence data we identified divergent and abundant bacteria in Haemaphysalis, Ixodes, Dermacentor and Carios ticks, including nine species of pathogenetic bacteria and potentially new species within the genus Borrelia. We also used these data to explore the evolutionary relationship between ticks and their associated bacteria, revealing a pattern of long-term co-divergence relationship between ticks and Rickettsia and Coxiella bacteria.

CONCLUSIONS: In sum, our study provides important new information on the genetic diversity of ticks based on an analysis of mitochondrial DNA as well as on the prevalence of tick-borne pathogens in China. It also sheds new light on the long-term evolutionary and ecological relationships between ticks and their associated bacteria.

RevDate: 2022-09-30
CmpDate: 2022-09-30

Chai J, Liu X, Usdrowski H, et al (2022)

Geography, niches, and transportation influence bovine respiratory microbiome and health.

Frontiers in cellular and infection microbiology, 12:961644.

Bovine respiratory disease (BRD), one of the most common and infectious diseases in the beef industry, is associated with the respiratory microbiome and stressors of transportation. The impacts of the bovine respiratory microbiota on health and disease across different geographic locations and sampling niches are poorly understood, resulting in difficult identification of BRD causes. In this study, we explored the effects of geography and niches on the bovine respiratory microbiome and its function by re-analyzing published metagenomic datasets and estimated the main opportunistic pathogens that changed after transportation. The results showed that diversity, composition, structure, and function of the bovine nasopharyngeal microbiota were different across three worldwide geographic locations. The lung microbiota also showed distinct microbial composition and function compared with nasopharyngeal communities from different locations. Although different signature microbiota for each geographic location were identified, a module with co-occurrence of Mycoplasma species was observed in all bovine respiratory communities regardless of geography. Moreover, transportation, especially long-distance shipping, could increase the relative abundance of BRD-associated pathogens. Lung microbiota from BRD calves shaped clusters dominated with different pathogens. In summary, geography, sampling niches, and transportation are important factors impacting the bovine respiratory microbiome and disease, and clusters of lung microbiota by different bacterial species may explain BRD pathogenesis, suggesting the importance of a deeper understanding of bovine respiratory microbiota in health.

RevDate: 2022-09-30
CmpDate: 2022-09-30

Kang JTL, Teo JJY, Bertrand D, et al (2022)

Long-term ecological and evolutionary dynamics in the gut microbiomes of carbapenemase-producing Enterobacteriaceae colonized subjects.

Nature microbiology, 7(10):1516-1524.

Long-term colonization of the gut microbiome by carbapenemase-producing Enterobacteriaceae (CPE) is a growing area of public health concern as it can lead to community transmission and rapid increase in cases of life-threatening CPE infections. Here, leveraging the observation that many subjects are decolonized without interventions within a year, we used longitudinal shotgun metagenomics (up to 12 timepoints) for detailed characterization of ecological and evolutionary dynamics in the gut microbiome of a cohort of CPE-colonized subjects and family members (n = 46; 361 samples). Subjects who underwent decolonization exhibited a distinct ecological shift marked by recovery of microbial diversity, key commensals and anti-inflammatory pathways. In addition, colonization was marked by elevated but unstable Enterobacteriaceae abundances, which exhibited distinct strain-level dynamics for different species (Escherichia coli and Klebsiella pneumoniae). Finally, comparative analysis with whole-genome sequencing data from CPE isolates (n = 159) helped identify substrain variation in key functional genes and the presence of highly similar E. coli and K. pneumoniae strains with variable resistance profiles and plasmid sharing. These results provide an enhanced view into how colonization by multi-drug-resistant bacteria associates with altered gut ecology and can enable transfer of resistance genes, even in the absence of overt infection and antibiotic usage.

RevDate: 2022-09-29
CmpDate: 2022-09-29

Kim DW, Ahn JH, CJ Cha (2022)

Biodegradation of plastics: mining of plastic-degrading microorganisms and enzymes using metagenomics approaches.

Journal of microbiology (Seoul, Korea), 60(10):969-976.

Plastic pollution exacerbated by the excessive use of synthetic plastics and its recalcitrance has been recognized among the most pressing global threats. Microbial degradation of plastics has gained attention as a possible eco-friendly countermeasure, as several studies have shown microbial metabolic capabilities as potential degraders of various synthetic plastics. However, still defined biochemical mechanisms of biodegradation for the most plastics remain elusive, because the widely used culture-dependent approach can access only a very limited amount of the metabolic potential in each microbiome. A culture-independent approach, including metagenomics, is becoming increasingly important in the mining of novel plastic-degrading enzymes, considering its more expanded coverage on the microbial metabolism in microbiomes. Here, we described the advantages and drawbacks associated with four different metagenomics approaches (microbial community analysis, functional metagenomics, targeted gene sequencing, and whole metagenome sequencing) for the mining of plastic-degrading microorganisms and enzymes from the plastisphere. Among these approaches, whole metagenome sequencing has been recognized among the most powerful tools that allow researchers access to the entire metabolic potential of a microbiome. Accordingly, we suggest strategies that will help to identify plastisphere-enriched sequences as de novo plastic-degrading enzymes using the whole metagenome sequencing approach. We anticipate that new strategies for metagenomics approaches will continue to be developed and facilitate to identify novel plastic-degrading microorganisms and enzymes from microbiomes.

RevDate: 2022-09-29
CmpDate: 2022-09-29

Seong HJ, Roux S, Hwang CY, et al (2022)

Marine DNA methylation patterns are associated with microbial community composition and inform virus-host dynamics.

Microbiome, 10(1):157.

BACKGROUND: DNA methylation in prokaryotes is involved in many different cellular processes including cell cycle regulation and defense against viruses. To date, most prokaryotic methylation systems have been studied in culturable microorganisms, resulting in a limited understanding of DNA methylation from a microbial ecology perspective. Here, we analyze the distribution patterns of several microbial epigenetics marks in the ocean microbiome through genome-centric metagenomics across all domains of life.

RESULTS: We reconstructed 15,056 viral, 252 prokaryotic, 56 giant viral, and 6 eukaryotic metagenome-assembled genomes from northwest Pacific Ocean seawater samples using short- and long-read sequencing approaches. These metagenome-derived genomes mostly represented novel taxa, and recruited a majority of reads. Thanks to single-molecule real-time (SMRT) sequencing technology, base modification could also be detected for these genomes. This showed that DNA methylation can readily be detected across dominant oceanic bacterial, archaeal, and viral populations, and microbial epigenetic changes correlate with population differentiation. Furthermore, our genome-wide epigenetic analysis of Pelagibacter suggests that GANTC, a DNA methyltransferase target motif, is related to the cell cycle and is affected by environmental conditions. Yet, the presence of this motif also partitions the phylogeny of the Pelagibacter phages, possibly hinting at a competitive co-evolutionary history and multiple effects of a single methylation mark.

CONCLUSIONS: Overall, this study elucidates that DNA methylation patterns are associated with ecological changes and virus-host dynamics in the ocean microbiome. Video Abstract.

RevDate: 2022-09-29
CmpDate: 2022-09-29

Parida PK, Behera BK, Dehury B, et al (2022)

Community structure and function of microbiomes in polluted stretches of river Yamuna in New Delhi, India, using shotgun metagenomics.

Environmental science and pollution research international, 29(47):71311-71325.

The large population residing in the northern region of India surrounding Delhi mostly depends on water of River Yamuna, a tributary of mighty Ganga for agriculture, drinking and various religious activities. However, continuous anthropogenic activities mostly due to pollution mediated by rapid urbanization and industrialization have profoundly affected river microflora and their function thus its health. In this study, potential of whole-genome metagenomics was exploited to unravel the novel consortia of microbiome and their functional potential in the polluted sediments of the river at Delhi. Analysis of high-quality metagenome data from Illumina NextSeq500 revealed substantial differences in composition of microbiota at different sites dominated by Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Chloroflexi phyla. The presence of highly dominant anaerobic bacteria like Dechloromonas aromatica (benzene reducing and denitrifying), Rhodopseudomonas palustris (organic matter reducing), Syntrophus aciditrophicus (fatty acid reducing) and Syntrophobacter fumaroxidans (sulphate reducing) in the polluted river Yamuna signifies the impact of unchecked pollution in declining health of the river ecosystem. A decline in abundance of phages was also noticed along the downstream river Yamuna. Mining of mycobiome reads uncovered plethora of fungal communities (i.e. Nakaseomyces, Aspergillus, Schizosaccharomyces and Lodderomyces) in the polluted stretches due to the availability of higher organic carbon and total nitrogen (%) could be decoded as promising bioindicators of river trophic status. Pathway analysis through KEGG revealed higher abundance of genes involved in energy metabolism (nitrogen and sulphur), methane metabolism, degradation of xenobiotics (Nitrotoluene, Benzoate and Atrazine), two-component system (atoB, cusA and silA) and membrane transport (ABC transporters). Catalase-peroxidase and 4-hydroxybenzoate 3-monooxygenase were the most enriched pollution degrading enzymes in the polluted study sites of river Yamuna. Overall, our results provide crucial insights into microbial dynamics and their function in response to high pollution and could be insightful to the ongoing remediation strategies to clean river Yamuna.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Li ML, Wang S, Xu P, et al (2022)

Functional genomics analysis reveals the evolutionary adaptation and demographic history of pygmy lorises.

Proceedings of the National Academy of Sciences of the United States of America, 119(40):e2123030119.

Lorises are a group of globally threatened strepsirrhine primates that exhibit many unusual physiological and behavioral features, including a low metabolic rate, slow movement, and hibernation. Here, we assembled a chromosome-level genome sequence of the pygmy loris (Xanthonycticebus pygmaeus) and resequenced whole genomes from 50 pygmy lorises and 6 Bengal slow lorises (Nycticebus bengalensis). We found that many gene families involved in detoxification have been specifically expanded in the pygmy loris, including the GSTA gene family, with many newly derived copies functioning specifically in the liver. We detected many genes displaying evolutionary convergence between pygmy loris and koala, including PITRM1. Significant decreases in PITRM1 enzymatic activity in these two species may have contributed to their characteristic low rate of metabolism. We also detected many evolutionarily convergent genes and positively selected genes in the pygmy loris that are involved in muscle development. Functional assays demonstrated the decreased ability of one positively selected gene, MYOF, to up-regulate the fast-type muscle fiber, consistent with the lower proportion of fast-twitch muscle fibers in the pygmy loris. The protein product of another positively selected gene in the pygmy loris, PER2, exhibited weaker binding to the key circadian core protein CRY, a finding that may be related to this species' unusual circadian rhythm. Finally, population genomics analysis revealed that these two extant loris species, which coexist in the same habitat, have exhibited an inverse relationship in terms of their demography over the past 1 million years, implying strong interspecies competition after speciation.

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