Argeting the trimethylamine-producing bacteria of the human gut microbiota
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB14888 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Choline is a water-soluble nutrient essential for human life. Gut microbial metabolism of choline results in the production of trimethylamine (TMA), which upon absorption by the host is converted in the liver to trimethylamine N-oxide (TMAO). Recent studies revealed that TMAO exacerbates atherosclerosis in mice, and positively correlates with the severity of this disease in human. However, which microbes contribute to TMA production in the human gut; the extent to which host factors, e.g., genotype and diet, affect TMA production and colonization of these microbes; as well as the effects TMA-producing microbes have on bioavailability of dietary choline remain largely unknown. We screened a collection of 78 sequenced human intestinal isolates encompassing the major phyla found in the human gut and identified eight strains capable of producing TMA from choline in vitro. Gnotobiotic mouse studies showed that TMAO accumulates in the serum of animals colonized with TMA-producing species, but not in the serum of animals colonized with intestinal isolates that do not generate TMA from choline in vitro. Remarkably, low levels of colonization of TMA-producing bacteria significantly reduced choline levels available to the host. This effect was more pronounced as the abundance of TMA-producing bacteria increased. Our findings provide a framework for designing strategies aimed at changing the representation or activity of TMA-producing bacteria in the human gut and suggest the TMA producing status of the gut microbiota should be considered when making recommendations about choline intake requirements for humans.
2015-04-02 | GSE63461 | GEO
Project description:Background: Probiotic-like bacteria treatment has been described to be associated with gut microbiota modifications. Goal: To decipher if the effects of the tested probiotic-like bacteria are due to the bacteria itself or due to the effects of the bacteria on the gut microbiota. Methodology: In this study, gut microbiota has been analyzed from feces samples of subjects with metabolic syndrome and treated with one of the 2 tested probiotic-like bacteria or with the placebo during 3months.
| EGAS00001003585 | EGA
Project description:Trimethylamine (TMA) is an important gut microbial metabolite strongly associated with human disease. There are prominent gaps in our understanding of how TMA is produced from the essential dietary nutrient L-carnitine, particularly in the anoxic environment of the human gut where oxygen-dependent L-carnitine-metabolizing enzymes are likely inactive. Here, we elucidate the chemical and genetic basis for anaerobic TMA generation from the L-carnitine-derived metabolite γ-butyrobetaine (γbb) by the human gut bacterium Emergencia timonensis. We identify a set of genes upregulated by γbb and demonstrate that the enzymes encoded by the induced γbb utilization (bbu) gene cluster convert γbb to TMA. The key TMA-generating step is catalyzed by a previously unknown type of TMA-lyase enzyme that utilizes a flavin cofactor to catalyze a redox neutral transformation. We identify additional cultured and uncultured host-associated bacteria that possess the bbu gene cluster, providing insights into the distribution of anaerobic γbb metabolism. Lastly, we present genetic, transcriptional, and metabolomic evidence that confirms the relevance of this metabolic pathway in the human gut microbiota. These analyses indicate that the anaerobic pathway is a more substantial contributor to TMA generation from L-carnitine in the human gut than the previously proposed aerobic pathway. The discovery and characterization of the bbu pathway provides the critical missing link in anaerobic metabolism of L-carnitine to TMA, enabling investigation into the connection between this microbial function and human disease.
2021-02-03 | GSE165976 | GEO
Project description: Not available
| S-EPMC5433236 | biostudies-literature
Project description:Given the criticle role of gut bacteria involve in number of diseases, the gut microbiota from young and aged people were estimated using 16s rRNA next-generation sequencing. This study will benefit to identify the role of gut bacteria on the pathegenic mechasim of aging relative diseases.
2022-07-20 | GSE165471 | GEO
Project description:Here we report 16s rRNA data in gut microbiota of hepatocellular carcinoma (HCC) patients with HBV induced HCC (HBVC) and non-HBV induced HCC (NHBVC) compared with healthy volunteers. A total of 2047 operational taxonomic units (OTUs) were identified in the sequence data. Our data shows that the NHBVC patients harbor lower anti-inflammatory bacteria and more pro-inflammatory bacteria, while the HBVC patients harbor more anti-inflammatory bacteria.
2019-02-27 | GSE108847 | GEO
Project description:The mammalian gut harbors a diverse microbial community (gut microbiota) that mainly consists of bacteria. Their combined genomes (the microbiome) provide biochemical and metabolic functions that complement host physiology. Maintaining symbiosis seems to be a key requirement for health as dysbiosis is associated with the development of common diseases. Previous studies indicated that the microbiota and the hostM-bM-^@M-^Ys epithelium signal bidirectional inducing transcriptional responses to fine-tune and maintain symbiosis. However, little is known about the hostM-bM-^@M-^Ys responses to the microbiota along the length of the gut as earlier studies of gut microbial ecology mostly used either colonic or fecal samples. This is of importance as not only function and architecture of the gut varies along its length but also microbial distribution and diversity. Few recent studies have begun to investigate microbiota-induced host responses along the length of the gut. However, these reports used whole tissue samples and therefore do not allow drawing conclusions about specificity of the observed responses. Which cells in the intestinal tissue are responsible for the microbially induced response: epithelial, mesenchymal or immune cells? Where are the responding cells located? Furthermore, the gut microbiota has been implicated in epigenetic regulation of the hostM-bM-^@M-^Ys transcriptional profile. We used using extensive microarray analysis of laser capture microdissection (LCM) harvested ileal and colonic tip and crypt fractions from germ-free mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) to investigate the microbiota-induced transcriptional responses and their kinetics in specific and well-defined cell populations of the hostM-bM-^@M-^Ys epithelium. Ileum and colon segments were dissected from germ-free 10-12 weeks old female C57Bl/6 mice and on day 1, 3, 5 and 7 after colonization, washed and frozen as OCT blocks. Cryosections were prepared from these OCT blocks and tip/crypt fractions isolated using laser capture microdissection. To investigate the microbiota-induced transcriptional responses specific for specific subpopulations of intestinal epithelial cells and their kinetics, tip and crypt fractions of ileal and colonic epithelium of germ-free 10-12 weeks old female C57Bl/6 mice before and during the time course of colonization with a normal microbiota (on days 1, 3, 5 and 7) were harvested using laser capture microdissection and probed in an extensive microarray analysis.
2015-02-12 | E-GEOD-51911 | biostudies-arrayexpress
Project description:BACKGROUND & AIMS: There is mounting evidence that microbes resident in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcoholic hepatitis (AH). However, mechanisms by which gut microbiota synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. METHODS: We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, and identified the metabolite trimethylamine (TMA) as a gut microbe-derived biomarker of AH. In subsequent studies, we treated mice with non-lethal mechanism-based bacterial choline TMA lyase inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. RESULTS: We show the gut microbial choline metabolite trimethylamine (TMA) is elevated in AH patients, which is correlated with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial choline TMA lyase activity protects mice from ethanol-induced liver injury. TMA lyase inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome community and host liver transcriptome. CONCLUSIONS: The microbial metabolite TMA is a biomarker of AH, and blocking TMA production from gut microbes can blunt ALD in mice.
2021-03-31 | GSE157681 | GEO
Project description:Gut microbiota dysbiosis characterizes systemic metabolic alteration, yet its causality is debated. To address this issue, we transplanted antibiotic-free conventional wild-type mice with either dysbiotic (“obese”) or eubiotic (“lean”) gut microbiota and fed them either a NC or a 72%HFD. We report that, on NC, obese gut microbiota transplantation reduces hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-transplanted mice. Of note, this phenotype is blunted in conventional NOD2KO mice. By contrast, lean microbiota transplantation did not affect hepatic gluconeogenesis. In addition, obese microbiota transplantation changed both gut microbiota and microbiome of recipient mice. Interestingly, hepatic gluconeogenesis, PEPCK and G6Pase activity were reduced even once mice transplanted with the obese gut microbiota were fed a 72%HFD, together with reduced fed glycaemia and adiposity compared to non-transplanted mice. Notably, changes in gut microbiota and microbiome induced by the transplantation were still detectable on 72%HFD. Finally, we report that obese gut microbiota transplantation may impact on hepatic metabolism and even prevent HFD-increased hepatic gluconeogenesis. Our findings may provide a new vision of gut microbiota dysbiosis, useful for a better understanding of the aetiology of metabolic diseases. all livers are from NC-fed mice only.
2017-03-16 | GSE81318 | GEO
Project description:The gut microbiota promotes immune system development in early life, but the interactions between the gut metabolome and immune cells in the neonatal gut remains largely undefined. Here, we demonstrate that the neonatal gut is uniquely enriched with neurotransmitters, including serotonin; specific gut bacteria produce serotonin directly while downregulating monoamine oxidase A to limit serotonin breakdown. Serotonin directly signals to T cells to increase intracellular indole-3-acetaldehdye to inhibit mTOR activation and thereby promotes the differentiation of regulatory T cells, both ex vivo and in vivo in the neonatal intestine. Oral gavage of serotonin into neonatal mice leads to long-term T cell-mediated antigen-specific immune tolerance towards both dietary antigens and commensal bacteria. Together, our study has uncovered an important role for unique gut bacteria to increase serotonin availability in the neonatal gut and a novel function of gut serotonin to shape T cell response to dietary antigens and commensal bacteria to promote immune tolerance in early life.
2024-01-31 | GSE248692 | GEO