Project description:Opioids such as morphine have many beneficial properties as analgesics, however, opioids may induce multiple adverse gastrointestinal symptoms. We have recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. However, it is unclear how opioids modulate the gut homeostasis. By using a mouse model of morphine treatment, we studied effects of morphine treatment on gut microbiome. We characterized phylogenetic profiles of gut microbes, and found a significant shift in the gut microbiome and increase of pathogenic bacteria following morphine treatment when compared to placebo. In the present study, wild type mice (C57BL/6J) were implanted with placebo, morphine pellets subcutaneously. Fecal matter were taken for bacterial 16s rDNA sequencing analysis at day 3 post treatment. A scatter plot based on an unweighted UniFrac distance matrics obtained from the sequences at OTU level with 97% similarity showed a distinct clustering of the community composition between the morphine and placebo treated groups. By using the chao1 index to evaluate alpha diversity (that is diversity within a group) and using unweighted UniFrac distance to evaluate beta diversity (that is diversity between groups, comparing microbial community based on compositional structures), we found that morphine treatment results in a significant decrease in alpha diversity and shift in fecal microbiome at day 3 post treatment compared to placebo treatment. Taxonomical analysis showed that morphine treatment results in a significant increase of potential pathogenic bacteria. Our study shed light on effects of morphine on the gut microbiome, and its role in the gut homeostasis.
Project description:Commensal bacteria can manipulate the proliferation, differentiation, and survival of intestinal epithelial cells. Hindlimb unloading alters the composition and structure of the microbial community. To further characterize the epithelial changes, we performed a genome-wide microarray analysis of colon epithelium isolated from HU and control mice.
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:To understand intestinal cell-specific responses to host commensal bacteria, we isolated single cells from intestines and associated tissue of zebrafish larvae raised in the presence or absence of a microbiome. We profiled cells with single-cell RNA-seq. Our analysis revealed extensive heterogeneity among cell populations of the fish intestine and associated tissue, and describe distinct microbial responses in each cell type.
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? We used using extensive microarray analysis of laser capture microdissection (LCM) harvested ileal and colonic tip and crypt fractions from germ-free and conventionally-raised mice to investigate the microbiota-induced transcriptional responses in specific and well-defined cell populations of the hostM-bM-^@M-^Ys epithelium. Ileum and colon segments were dissected from germ-free and conventionally-raised 10-12 weeks old female C57Bl/6 mice, 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, tip and crypt fractions of ileal and colonic epithelium of germ-free and conventionally-raised 10-12 weeks old female C57Bl/6 mice were harvested using laser capture microdissection and probed in an extensive microarray analysis.
Project description:The human intestine is colonized with a complex microbial community and forms a super organism with the human body. Intestinal microorganisms include more than 1,000 kinds of bacterias, and their flora is very complex and functions are very diverse. The intestinal flora affects the body’s nutrition, immunity and metabolism through interaction with the human body and the external environment, and is closely related to multiple systems. When the flora structure and function are changed, it will lead to the occurrence of various diseases or increase the risk of disease. In recent years, the role of intestinal microbes in tumorigenesis and development, as well as the role of diagnosis and treatment have been paid more and more attention. Abnormal intestinal flora can not only promote tumorigenesis, but also affect radiochemotherapy and immunotherapy effects. It is worth noting that the huge impact of the intestinal flora on immunotherapy suggests that immune checkpoint inhibitors can maximize the efficacy by protecting the balance and diversity of the intestinal microecology. Therefore, in this study, quantitative analysis of the diversity and abundance of intestinal, urinary tract flora, and urine components before and after adjuvant chemotherapy in patients with gastric and bowel cancer was performed. The link between treatment efficacy and prognosis.
Project description:Small intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate. culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small-intestinal microbial diversity and small-intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment.
Project description:Folic acid deficiency is common worldwide and is linked to intestinal flora imbalance. The intestinal microbial utilization of folic acid based on model animals faces the challenges of repeatability and individual variability. In this study, we built an in vitro fecal slurry culture model deficient in folic acid. We examined the effects of supplementation with different forms of folic acid (5-methyltetrahydrofolate and non-reduced folic acid) on the modulation of intestinal flora. 16S rDNA gene sequencing showed alpha diversity increased after folic acid supplementation compared to fermentation samples with folic acid deficiency. In the non-reduced folic acid (FA) group, the relative abundance of the Firmicutes phylum dropped to 56.7%, whereas in the 5-methyltetrahydrofolate (MTHF) supplementation group, it grew to 64.9%. Lactobacillus genera became more prevalent, reaching 22.8% and 30.8%, respectively. Additionally, Bifidobacterium and Pedioccus, two common probiotic bacteria, were in higher abundance. Short-chain fatty acids (SCFAs) analysis showed that supplementation with folic acid (non-reduced folic acid, 5-methyltetrahydrofolate) decreased acetic acid and increased the fermentation yield of isobutyric acid. The in vitro fecal slurry culture model developed in this study can be utilized as a human folic acid deficiency model for studying intestinal microbiota and demonstrated that both 5-methyltetrahydrofolate and non-reduced folic acid have effects on the regulation of intestinal microecology.