Project description:This study employed low and high-fat purified diets containing two levels of added dietary cholesterol in conventionally raised, specific-pathogen free (SPF) mice harboring a full microbial community as compared to germ-free (GF) mice raised in complete absence of gut microbes on disease outcomes. It was hypothesized that FF-diets would lead to an earlier onset of gut dysbiosis, corresponding with elevated biomarkers of NAFLD and NASH. In the present study, we aimed to dissect the role of FF diet induced gut dysbiosis in order to mechanistically identify the underlying mechanism that influences gut-liver crosstalk between specific diet-induced bacterial populations and hepatic tissue to drive NAFLD/NASH onset and progression
Project description:In the presented study, in order to unravel gut microbial community multiplicity and the influence of maternal milk nutrients (i.e., IgA) on gut mucosal microbiota onset and shaping, a mouse GM (MGM) was used as newborn study model to discuss genetic background and feeding modulation on gut microbiota in term of symbiosis, dysbiosis and rebiosis maintenance during early gut microbiota onset and programming after birth. Particularly, a bottom-up shotgun metaproteomic approach, combined with a computational pipeline, has been compred with a culturomics analysis of mouse gut microbiota, obtained by MALDI-TOF mass spectrometry (MS).
Project description:Microbiota dysbiosis has been reported to contribute to the pathogenesis of colitis, to demonstrate whether IL-17D protects against DSS-induced colitis through regulation of microflora, we performed 16S rRNA sequencing in feces from WT and Il17d-deficient mice. Our data indicate that Il17d deficiency results in microbiota dysibiosis in both steady state and DSS-induced colitis.
Project description:In the DSS-induced colitis model, the epithelial damage and resulting inflammation is restricted to the colon, with a potential influence on the microbial composition in the adjacent cecum. Several studies have reported changes of the gut microbiota in the DSS-induced colitis model and other mouse models of IBD. Furthermore, metaproteomics analysis of the gut microbiome in a mouse model of Crohn’s disease demonstrated that disease severity and location are microbiota-dependent, with clear evidence for the causal role of bacterial dysbiosis in the development of chronic ileal inflammation. We have developed a refined model of chronic DSS-induced colitis that reflects typical symptoms of human IBD without a risky body weight loss usually observed in DSS models [Hoffmann et al., submitted]. In this study, we used metaproteomics to characterize the disease-related changes in bacterial protein abundance and function in the refined model of DSS-induced colitis. To assess the structural and functional changes, we applied 16S rRNA gene sequencing and metaproteomics analysis of the intestinal microbiota in three different entities of the intestinal environment, i.e. colon mucus, colon content and cecum content.
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.
Project description:DNA methylation profile of mouse sperm from conventionally-raised mice and gut dysbiosis experienced mice were characterized using whole-genome bisulfite sequencing. Genome-wide DNA methylation changes between control and dysbiotic male�s sperm were highly comparable, with no change in DNAme globally or at genomic features, only 21 differentially methylated regions (DMR) were identified, which did not overlap known regulatory elements. Epididymal sperm samples were harvested from 11 weeks old inbred male mice that were experiencing gut microbiota dysbiosis for 6-week (antibiotics treated, n=5), or drink sterilized water (control, n=5).
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host's mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:Gut microbiota and their metabolites influence host gene expression and physiological status through diverse mechanisms. Here we investigate how gut microbiota and their metabolites impact host′s mRNA m6A epitranscriptome in various antibiotic-induced microbiota dysbiosis models. With multi-omics analysis, we find that the imbalance of gut microbiota can rewire host mRNA m6A epitranscriptomic profiles in brain, liver and intestine. We further explore the underlying mechanisms regulating host mRNA m6A methylome by depleting the microbiota with ampicillin. Metabolomic profiling shows that cholic acids are the main down-regulated metabolites with Firmicutes as the most significantly reduced genus in ampicillin-treated mice comparing to untreated mice. Fecal microbiota transplantations in germ-free mice and metabolites supplementations in cells verify that cholic acids are associated with host mRNA m6A epitranscriptomic rewiring. Collectively, this study employs an integrative multi-omics analysis to demonstrate the impact of gut microbiota dysbiosis on host mRNA m6A epitranscriptomic landscape via cholic acid metabolism.
Project description:Morphine and its pharmacological derivatives are the most prescribed analgesics for moderate to severe pain management. However, chronic use of morphine reduces pathogen clearance and induces bacterial translocation across the gut barrier. The enteric microbiome has been shown to play a critical role in the preservation of the mucosal barrier function and metabolic homeostasis. Here, we show for the first time, using bacterial 16s rDNA sequencing, that chronic morphine treatment significantly alters the gut microbial composition and induces preferential expansion of the gram-positive pathogenic and reduction of bile-deconjugating bacterial strains. A significant reduction in both primary and secondary bile acid levels was seen in the gut, but not in the liver with morphine treatment. Morphine induced microbial dysbiosis and gut barrier disruption was rescued by transplanting placebo-treated microbiota into morphine-treated animals, indicating that microbiome modulation could be exploited as a therapeutic strategy for patients using morphine for pain management. In this study, we establish a link between the two phenomena, namely gut barrier compromise and dysregulated bile acid metabolism. We show for the first time that morphine fosters significant gut microbial dysbiosis and disrupts cholesterol/bile acid metabolism. Changes in the gut microbial composition is strongly correlated to disruption in host inflammatory homeostasis13,14 and in many diseases (e.g. cancer/HIV infection), persistent inflammation is known to aid and promote the progression of the primary morbidity. We show here that chronic morphine, gut microbial dysbiosis, disruption of cholesterol/bile acid metabolism and gut inflammation; have a linear correlation. This opens up the prospect of devising minimally invasive adjunct treatment strategies involving microbiome and bile acid modulation and thus bringing down morphine-mediated inflammation in the host.