Project description:v3-v4 16S rRNA sequencing was used to characterize both gut and oral microbiota composition of RCC (refractory chronic cough) patients and matched healthy controls (HC). The groups are matched in age and gender.
Project description:Irritable Bowel Syndrome (IBS) is a disorder of the gut-brain axis, characterized by altered gut function and frequent psychiatric co-morbidity. Although altered intestinal microbiome profiles have been documented, their relevance to the clinical expression of IBS is unknown. To evaluate a functional role of the microbiota, we colonized germ-free mice with fecal microbiota from healthy controls or IBS patients with accompanying anxiety, and monitored gut function and behavior. Mouse microbiota profiles clustered according to their human donors. Despite having taxonomically similar composition as controls, mice with IBS microbiota had distinct serum metabolomic profiles related to neuro- and immunomodulation. Mice with IBS, but not control microbiota, exhibited faster gastrointestinal transit, intestinal barrier dysfunction, innate immune activation and anxiety-like behavior. These results support the notion that the microbiota contributes to both intestinal and behavioral manifestations of IBS and rationalize the use of microbiota-directed therapies in ameliorating IBS.
Project description:Antemortem infection is a risk factor for sudden infant death syndrome (SIDS) – the leading postneonatal cause of infant mortality in the developed world. Manifestations of infection and attendant inflammation, however, are not always apparent in clinical settings or by standard autopsy, thus enhanced resolution approaches are needed. Here we screened postmortem SIDS tissues and fluids for inflammatory markers and applied metagenomics and transcriptomics to a subset of cases to look for evidence of occult infection and inflammation.
Project description:Regulatory T cells (Tregs) are immune cells that play a crucial role in maintaining tolerance to harmless antigens, including commensal microbes. In the intestine, Tregs can be classified into subsets based on their expression of transcription factors Helios, Rorg, Gata3 and cMaf. The exact functions of the intestinal Treg subsets and their role in maintaining tolerance to intestinal microbes is not fully understood. Here, we generated conditional knockout mice of each Treg subset and profiled the composition of their intestinal microbiota by performing 16S rRNA sequencing of stool from conditional knockouts and matched littermate controls.
Project description:The intestinal microbiota has been identified as an environmental factor that markedly impacts energy storage and body fat accumulation, yet the underlying mechanisms remain unclear. Here we show that the microbiota regulates body composition through the circadian transcription factor NFIL3. Nfil3 transcription oscillates diurnally in intestinal epithelial cells and the amplitude of the circadian oscillation is controlled by the microbiota through type 3 innate lymphoid cells (ILC3), STAT3, and the epithelial cell circadian clock. NFIL3 controls expression of a circadian lipid metabolic program and regulates lipid absorption and export in intestinal epithelial cells. These findings provide mechanistic insight into how the intestinal microbiota regulates body composition and establish NFIL3 as an essential molecular link among the microbiota, the circadian clock, and host metabolism.
Project description:Alterations in intestinal microbiota and intestinal short chain fatty acids profiles have been associated with the pathophysiology of obesity and insulin resistance. Whether intestinal microbiota dysbiosis is a causative factor in humans remains to be clarified We examined the effect of fecal microbial infusion from lean donors on the intestinal microbiota composition, glucose metabolism and small intestinal gene expression. Male subjects with metabolic syndrome underwent bowel lavage and were randomised to allogenic (from male lean donors with BMI<23 kg/m2, n=9) or autologous (reinfusion of own feces, n=9) fecal microbial transplant. Insulin sensitivity and fecal short chain fatty acid harvest were measured at baseline and 6 weeks after infusion. Intestinal microbiota composition was determined in fecal samples and jejunal mucosal biopsies were also analyzed for the host transcriptional response. Insulin sensitivity significantly improved six weeks after allogenic fecal microbial infusion (median Rd: from 26.2 to 45.3 μmol/kg.min, p<0.05). Allogenic fecal microbial infusion increased the overall amount of intestinal butyrate producing microbiota and enhanced fecal harvest of butyrate. Moreover, the transcriptome analysis of jejunal mucosal samples revealed an increased expression of genes involved in a G-protein receptor signalling cascade and subsequently in glucose homeostasis. Lean donor microbial infusion improves insulin sensitivity and levels of butyrate-producing and other intestinal microbiota in subjects with the metabolic syndrome. We propose a model wherein these bacteria provide an attractive therapeutic target for insulin resistance in humans. (Netherlands Trial Register NTR1776).
Project description:Maternal secretor status is one of the determinants of human milk oligosaccharides (HMOs) composition, which in turn changes the gut microbiota composition of infants. To understand if this change in gut microbiota impacts immune cell composition, intestinal morphology and gene expression, day 21-old germ-free mice were transplanted with fecal microbiota from infants whose mothers were either secretors (SMM) or non-secretors (NSM) or from infants consuming dairy-based formula (MFM). For each group, one set of mice was supplemented with HMOs. HMO supplementation did not significantly impact the microbiota diversity however, SMM mice had higher abundance of genus Bacteroides, Bifidobacterium, and Blautia, whereas, in the NSM group, there were higher abundance of Akkermansia, Enterocloster, and Klebsiella. In MFM, gut microbiota was represented mainly by Parabacteroides, Ruminococcaceae_unclassified, and Clostrodium_sensu_stricto. In mesenteric lymph node, Foxp3+ T cells and innate lymphoid cells type 2 (ILC2) were increased in MFM mice supplemented with HMOs while in the spleen, they were increased in SMM+HMOs mice. Similarly, serum immunoglobulin A (IgA) was also elevated in MFM+HMOs group. Distinct global gene expression of the gut was observed in each microbiota group, which was enhanced with HMOs supplementation. Overall, our data shows that distinct infant gut microbiota due to maternal secretor status or consumption of dairy-based formula and HMO supplementation impacts immune cell composition, antibody response and intestinal gene expression in a mouse model.
Project description:The cytokine TNF drives inflammatory diseases, e.g. Crohn disease. In a mouse model of TNF-induced systemic inflammatory response syndrome (SIRS), severe impact on intestinal epithelial cells (IECs) is observed. Zinc confers complete protection in this model. We found that zinc no longer protects in animals which lack glucocorticoids (GCs), or express mutant versions of their receptor GR in IECs, nor in mice which lack gut microbiota. RNA-seq studies in IECs showed that zinc caused reduction of expression of constitutive (STAT1-induced) interferon-stimulated response (ISRE) genes and Interferon Regulatory Factor (IRF) genes. Since some of these genes are involved in TNF-induced cell death in intestinal crypt Paneth cells, and since zinc has direct effects on the composition of the gut microbiota (such as several Staphylococcus species) and on TNF-induced Paneth cell death, we postulate a new zinc-related anti-inflammatory mechanism. Zinc modulates the gut microbiota, causing less induction of ISRE/IRF genes in crypt cells, less TNF-induced necroptosis in Paneth cells and less fatal evasion of gut bacteria into the system.