Project description:The human gut microbiota impacts host metabolism and has been implicated in the pathophysiology of obesity and metabolic syndromes. However, defining the roles of specific microbial activities and metabolites on host phenotypes has proven challenging due to the complexity of the microbiome-host ecosystem. Here, we identify strains from the abundant gut bacterial phylum Bacteroidetes that display selective bile salt hydrolase (BSH) activity. Using isogenic strains of wild-type and BSH-deleted Bacteroides thetaiotaomicron, we selectively modulated the levels of the bile acid tauro-b-muricholic acid in monocolonized gnotobiotic mice. B. thetaiotaomicron BSH mutant-colonized mice displayed altered metabolism, including reduced weight gain and respiratory exchange ratios, as well as transcriptional changes in metabolic, circadian rhythm, and immune pathways in the gut and liver. Our results demonstrate that metabolites generated by a single microbial gene and enzymatic activity can profoundly alter host metabolism and gene expression at local and organism-level scales.

2018-07-19 | GSE112571 | GEO

Regulation of host weight gain and lipid metabolism by bacterial bile acid modification in the gut

Project description:Alterations in the gastrointestinal microbiota have been implicated in obesity in mice and humans, but the conserved microbial functions that influence host energy metabolism and adiposity have not been determined. Here we show that bacterial bile salt hydrolase (BSH) controls a microbe-host dialogue which functionally regulates host lipid metabolism and weight gain. Expression of cloned BSH enzymes in the GI tract of gnotobiotic or conventional mice significantly altered plasma bile acid signatures and regulated transcription of key genes involved in lipid metabolism (PPARgamma angptl4), cholesterol metabolism (abcg5/8), gastrointestinal homeostasis (regIIIgamma) and circadian rhythm (dbp, per1/2) in the liver or small intestine. High-level expression of BSH in conventionally raised mice resulted in significant reduction of host weight-gain, plasma cholesterol and liver triglycerides. We demonstrate that bacterial BSH activity significantly impacts systemic metabolic processes and adiposity in the host, and represents a key mechanistic target for the control of obesity and hypercholesterolaemia. Germ free Swiss Webster mice were monocolonised with EC containing the bacterial gene, Bile salt hydroalse. The treatment groups and relevant controls were; 1. Germ Free(GF) n=4 , 2. GF and EC n=4, 3. GF and EC +BSH1 n=4, 4. GF and EC+ BSH2 n=4, 5. GF re-conventionalised (CONV-D) n= 5. The Ileum and Liver were removed and the RNA extracted (RNAeasy plus universal kit (Qiagen), quantified and Microarrays were carried out using mouse Exon ST1.0 arrays (Affymetrix) by Almac Group, Craigavon, Northern Ireland. Analysis and pathway mapping was carried out by ALMAC and using Subio Platform software (Subio Inc) and Genesis Software.

2014-05-09 | E-GEOD-46952 | biostudies-arrayexpress

Opioid-induced gut microbial disruption leads to gut barrier compromise and sustained systemic inflammation.

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.

2016-06-01 | E-MTAB-3722 | biostudies-arrayexpress

Gene Array to Predict Bacterial Infection with in Respiratory Illness

Project description:<p>Accurate tests for microbiologic diagnosis of lower respiratory tract infections (LRTI) are needed. Gene expression profiling of whole blood represents a powerful new approach for analysis of the host response during respiratory infection that can be used to supplement pathogen detection testing. Using qPCR, we prospectively validated the differential expression of 10 genes previously shown to discriminate bacterial and non-bacterial LRTI confirming the utility of this approach. In addition, a novel approach using RNAseq analysis identified 141 genes differentially expressed in LRTI subjects with bacterial infection. Using "pathway-informed" dimension reduction, we identified a novel 11 gene set (selected from lymphocyte, α-linoleic acid metabolism, and IGF regulation pathways) and demonstrated a predictive accuracy for bacterial LRTI (nested CV-AUC=0.87). RNAseq represents a new and an unbiased tool to evaluate host gene expression for the diagnosis of LRTI.</p>

| phs001248 | dbGaP

RNAseq of C. elegans cultured on metformin sensitive and resistant E. coli strains with and without 50mM metformin treatment.

Project description:Metformin is the therapy of choice for treating type 2 diabetes and is currently repurposed for a wide range of diseases including aging. Recent evidence implicates the gut microbiota as a site of metformin action. Combining two tractable genetic models, the bacterium E. coli and the nematode C. elegans, we performed C. elegans RNAseq to investigate the role of the metformin sensitive OP50 and metformin resistant OP50-MR E. coli microbiota in the drug effects on the host. Our data suggest an evolutionarily conserved bacterial mediation of metformin effects on host lipid metabolism and lifespan.

2019-07-13 | E-MTAB-7272 | biostudies-arrayexpress

Wildtype and NRP1 knockout macrophages

Project description:Obesity gives rise to metabolic complications by mechanisms that are poorly understood. While chronic inflammatory signaling in adipose tissue is typically associated with metabolic deficiencies linked to excessive weight gain, we identified a subset of NRP1-expressing myeloid cells that accumulate in adipose tissue and protect against obesity and metabolic syndrome. Ablation of NRP1 in macrophages compromised lipid uptake in these cells, which reduced substrates for fatty acid β-oxidation and shifted energy metabolism of these macrophages towards a more inflammatory glycolytic metabolism. Conditional deletion of NRP1 in LysM Cre-expressing cells lead to inadequate adipose vascularization, accelerated weight gain and reduced insulin sensitivity even independent of weight gain. Transfer of NRP1+ hematopoietic cells improved glucose homeostasis, resulting in the reversal of a prediabetic phenotype. Our findings suggest a pivotal role for adipose tissue resident NRP1+-expressing macrophages in driving healthy weight gain and maintaining glucose tolerance.

2018-02-11 | GSE110447 | GEO

The host & gut microbiome orchestrate smoking cessation-induced weight gain

Project description:The host & gut microbiome orchestrate smoking cessation-induced weight gain

| PRJEB47053 | ENA

Altered adipose lipid mobilization predicts long-term weight gain and impaired glucose metabolism

Project description:Altered adipose lipid mobilization predicts long-term weight gain and impaired glucose metabolism

| PRJNA449938 | ENA