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: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:Periodontitis patients often develop bacteremia, but there has been little evidence showing that oral bacteria translocate into other organs. We found that bacterial colony formation occurs in a culture of liver and spleen cells of periodontitis-induced mice, and the bacterial species detected in the liver and spleen were found in the oral cavity as well, but not in fecal samples, indicating systemic dissemination of oral bacteria during the breakdown of the oral barrier.
Project description:<p>In this study, we investigated the role of the gut microbiota on the development of complications in kidney transplant recipients. We collected serial fecal specimens from 168 kidney transplant recipients within the first 3 months after transplantation. We performed 16S rRNA gene sequencing of the V4-V5 hypervariable region and examined whether the relative gut abundance of pathogenic bacteria was associated with future development of complications like bacteriuria and urinary tract infections. In a subset of samples, we performed metagenomic sequencing of stool and urine supernatant specimens to determine strain level analysis. </p>
Project description:Distal gut bacteria play a pivotal role in the digestion of dietary polysaccharides by producing a large number of carbohydrate-active enzymes (CAZymes) that the host otherwise does not produce. We report here the design of a high density custom microarray that we used to spot non-redundant DNA probes for more than 6,500 genes encoding glycoside hydrolases and lyases selected from 174 reference genomes from distal gut bacteria. The custom microarray was tested and validated by the hybridization of bacterial DNA extracted from the stool samples of lean, obese and anorexic individuals. Our results suggest that a microarray-based study can detect genes from low-abundance bacteria better than metagenomic-based studies. A striking example was the finding that a gene encoding a GH6-family cellulase was present in all subjects examined, whereas metagenomic studies have consistently failed to detect this gene in both human and animal gut microbiomes. In addition, an examination of eight stool samples allowed the identification of a corresponding CAZome core containing 46 families of glycoside hydrolases and polysaccharide lyases, which suggests the functional stability of the gut microbiota despite large taxonomical variations between individuals. Fecal samples were collected from eight female subjects. Three were obese subjects of BMI kg m-2: 35, 46.8 and 51.3, respectively; age: 42, 21 and 65 years old, respectively. Three were anorexic women of BMI kg m-2: 9.8, 10 and 13.7, respectively; age: 19, 23 and 49 years old, respectively. Finally, two fecal samples from lean women of BMI kg m-2: 18.6 and 23.42 were analyzed.
Project description:We used 16S V3/V4 region amplification to evaluate the composition of bacteria species in mouse fecal pellets. Fecel pellets were collected from young-adult (12 weeks old) wild type C57Bl/6 mice and aged (72 weeks old) wild type C57Bl/6 mice after 21 days of vehicle or antibiotics treatment (to induce gut microbiota depletion). In one sequencing round, we sequenced a total of 12 different fecal samples (3 young control, 3 aged control, 3 young depleted gut microbiota (ABX) and 3 aged depleted gut microbiota (ABX)). Amplicons were indexed using the Nextera XT Index Kit and pooled into a library for Illumina sequencing.
Project description:Necrotizing enterocolitis (NEC) is an acute and life-threatening gastrointestinal disorder afflicting preterm infants, which is currently unpreventable. Fecal microbiota transplantation (FMT) is a promising preventative therapy, but potential bacterial infection raise concern. Removal of bacteria from donor feces may reduce this risk while maintaining the NEC-preventive effects. We aimed to assess preclinical efficacy and safety of bacteria-free fecal filtrate transfer (FFT). Using fecal material from healthy suckling piglets, we administered FMT rectally, or cognate FFT either rectally or oro-gastrically to formula-fed preterm, cesarean-delivered piglets as a model for preterm infants, We compared gut pathology and related safety parameters with saline controls, and analyzed ileal mucosal transcriptome to gauge the host e response to FMT and FFT treatments relative to control. Results showed that oro-gastric FFT prevented NEC, whereas FMT did not perform better than control. Moreover, FFT but not FMT reduced intestinal permeability, whereas FMT animals had reduced body weight increase and intestinal growth. Global gene expression of host mucosa responded to FMT but not FFT with increased and decreased bacterial and viral defense mechanisms, respectively. In conclusion, as preterm infants are extremely vulnerable to enteric bacterial infections, rational NEC-preventive strategies need incontestable safety profiles. Here we show in a clinically relevant animal model that FFT, as opposed to FMT, efficiently prevents NEC without any recognizable side effects. If translatable to preterm infants, this could lead to a change of practice and in turn a reduction in NEC burden.
Project description:We found that low protein diet consumption resulted in decrease in the percentage of normal Paneth cell population in wild type mice, indicating that low protein diet could negatively affect Paneth cell function. We performed fecal microbiota composition profiling. Male mice were used at 4-5 weeks of age. Fecal samples were collected for microbiome analysis.
Project description:Microbiota dysbiosis and mucosa-associated bacteria are involved in colorectal cancer progression. We hypothesized that a time-specific interaction between dysbiotic pathobionts and host responses promote tumor growth. This study aimed to elucidate the dysfunctional host-microbe interplay in colon tumorigenesis by using a time-series metagenomics approach. A transient surge in fecal microbial richness was linked to a unique transcriptome profile in the mouse colon during carcinoma transformation. Monitoring gut microbiome may help identifying the window-of-opportunity to induce tumor regression using bacteria-targeted precision medicine.