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:Age-dependent changes of the gut-associated microbiome have been linked to increased frailty and systemic inflammation. This study found that age-associated changes of the gut microbiome of BALB/c and C57BL/6 mice could be reverted by co-housing of aged (22 months old) and adult (3 months old) mice for 30-40 days or faecal microbiota transplantation (FMT) from adult into aged mice. This was demonstrated using high-throughput sequencing of the V3-V4 hypervariable region of bacterial 16S rRNA gene isolated from faecal pellets collected from 3-4 months old adult and 22-23 months old aged mice before and after co-housing or FMT.
Project description:In rodents, brown adipose tissue (BAT) contributes to whole body energy expenditure and low BAT activity is related to hepatic fat accumulation, partially attributable to the gut microbiome. Little is known of these relationships in humans. In adults (n=60), we assessed hepatic fat and cold-stimulated BAT activity utilizing magnetic resonance imaging and the gut microbiome with 16S sequencing. We transplanted gnotobiotic mice with feces from humans to assess the transferability of BAT activity and NAFLD through the microbiome. Individuals with NAFLD (n=29) had lower BAT activity than those without and BAT activity was inversely related to hepatic fat. Although the fecal microbiome was different in those with NAFLD, no differences were observed in relation to BAT activity and neither of these phenotypic traits were transmissible through fecal transplant to gnotobiotic mice. Thus, low BAT activity is associated with hepatic steatosis but this is not mediated through the gut microbiota.
Project description:Purpose: To study the differential expression of gut bacterial mRNAs during chronic organophosphate treatment. Methods: Balb/c mice were treated with organophosphate (monocrotophos 28 ug/kg body weight/day) directly in drinking water for 180 days. Glucose tolerance tests indicated the induction of glucose intolerance. The total RNA was isolated by using TRIZOL from the cecal tissue that is cleared off fecal contents and subsequently the eukaryotic and bacterial rRNAs were removed by using MicrobExpress and MicrobEnrich kits (Ambion). Subsequently, RNA library was contructed using illumina kit as per manufacturer's instructions. Results: The reads were annotated to the reference human gut microbiome database and we found differential expression of large number of genes especially those involved in organophosphate degradation. Our subsequent studies proved that gut microbial degradation of organophosphates induces glucose intolerance via gluconeogenesis. Conclusions: Chronic organophosphate-induced hyperglycemia is mediated by the organosphosphate-degrading potential of gut microbiota.
Project description:Aims Gut microbiota-mediated inflammation promotes obesity-associated low-grade inflammation, which represents a hallmark of the metabolic syndrome (MetS). Lifestyle-induced weight loss (WL) is regarded as an efficient therapy to reverse MetS and to prevent disease progression. The objective of this study was to investigate if lifestyle-induced WL modulates the gut microbiome and its interaction with the host. Methods We analyzed and compared the fecal metaproteome of 33 individuals with MetS in a longitudinal study before and after lifestyle-induced WL in a well-defined cohort (ICTRP Trial Number: U1111-1158-3672). Results The 6-month WL intervention resulted in reduced BMI (-13.9%), increased insulin sensitivity (HOMA-IR; -53.70%) and reduced levels of circulating CRP (-66.86%), indicating MetS reversal. The metaprotein spectra of the host revealed a decrease of human proteins associated with gut inflammation and reduced abundance of human pancreatic alpha-amylase. Surprisingly, taxonomic analysis of the fecal metaproteome revealed only minor changes in the bacterial composition with an increase of low-abundant families (Desulfovibrionaceae, Leptospiraceae, Syntrophomonadaceae, Thermotogaceae, Verrucomicrobiaceae). Yet, we detected increased abundance of microbial metaprotein spectra that correspond to enhanced hydrolysis of complex carbohydrates (endoglucanase A, β-1,4-mannooligosaccharide phosphorylase, galactokinase, 5-keto-D-gluconate 5-reductase), indicating functional changes of the gut microbiome. Conclusions Our results indicate that lifestyle induced WL may improve interaction between the gut microbiome and the host in individuals with MetS, while bacterial composition remained almost stable. Metaproteome analysis of host proteins reveals reduced gut inflammation whereas microbial metaprotein spectra indicate functional changes towards degradation of complex carbohydrates. The filenames correspond to the ID of the patient (1-33), whereas “C” corresponds to baseline and “ABC” to weight loss.
Project description:Significant gut microbiota heterogeneity exists amongst UC patients though the clinical implications of this variance are unknown. European and South Asian UC patients exhibit distinct disease risk alleles, many of which regulate immune function and relate to variation in gut microbiota β-diversity. We hypothesized ethnically distinct UC patients exhibit discrete gut microbiotas with unique luminal metabolic programming that influence adaptive immune responses and relate to clinical status. Using parallel bacterial 16S rRNA and fungal ITS2 sequencing of fecal samples (UC n=30; healthy n=13), we corroborated previous observations of UC-associated depletion of bacterial diversity and demonstrated significant gastrointestinal expansion of Saccharomycetales as a novel UC characteristic. We identified four distinct microbial community states (MCS 1-4), confirmed their existence using microbiota data from an independent UC cohort, and show they co-associate with patient ethnicity and degree of disease severity. Each MCS was predicted to be uniquely enriched for specific amino acid, carbohydrate, and lipid metabolism pathways and exhibited significant luminal enrichment of metabolic products from these pathways. Using a novel in vitro human DC/T-cell assay we show that DC exposure to patient fecal water led to MCS -specific changes in T-cell populations, particularly the Th1:Th2 ratio, and that patients with the most severe disease exhibited the greatest Th2 skewing. Thus, based on ethnicity, microbiome composition, and associated metabolic dysfunction, UC patients may be stratified in a clinically and immunologically meaningful manner, providing a platform for the development of FMC-focused therapy. Fecal microbiome was assessed with Affymetrix PhyloChip arrays from patients with ulcerative colitis and healthy controls.
Project description:The human gut microbiota harbors methanogens represented by the dominant archaeon, Methanobrevibacter smithii, a polyphyletic group of acetogens, and sulfate-reducing bacteria. Defining their roles in the H2-economy of the gut has potential therapeutic importance for modulating the efficiency of fermentation of dietary components. We quantified methanogens in fecal samples from 40 healthy adult female monozygotic(MZ) and 28 dizygotic(DZ) twin pairs, analyzed bacterial 16S rRNA datasets generated from their fecal samples to identify taxa that co-occur with methanogens, sequenced the genomes of 20 M. smithii strains isolated from families of MZ and DZ twins, and performed RNA-Seq of a subset of strains to identify their responses to varied formate concentrations. The concordance rate for methanogen carriage was significantly higher for MZ versus DZ twin pairs. Co-occurrence analysis revealed 22 bacterial species-level taxa positively correlated with methanogens: all but two were members of the Clostridiales, with several being, or related to, known hydrogen-producing and -consuming bacteria. The M. smithii pan-genome contains 987 genes conserved in all strains, and 1860 variably represented genes. Strains from MZ and DZ twin pairs had a similar degree of shared genes and SNPs, and were significantly more similar than strains isolated from mothers or members of other families. The 101 adhesin-like proteins(ALPs) in the pan-genome (45±6/strain) exhibit strain-specific differences in expression and responsiveness to formate. We hypothesize that M. smithii strains use their different repertoires of ALPs to create diversity in their metabolic niches, by allowing them to establish syntrophic relationships with bacterial partners with differing metabolic capabilities and patterns of co-occurrence These strains were isolated from human feces, but they are in pure culture now. All the information about each species is associated with the genome accession number Fecal samples from 40 healthy adult female monozygotic(MZ) and 28 dizygotic(DZ) twin pairs, analyzed bacterial 16S rRNA datasets generated from their fecal samples to identify taxa that co-occur with methanogens, sequenced the genomes of 20 M. smithii strains isolated from families of MZ and DZ twins, and performed RNA-Seq of a subset of strains to identify their responses to varied formate concentrations. Strains of Methanobrevibacter smithii were grown in vitro (modified MBC media) to mid-log phase, at 37°C in serum bottles pressurized with 80% hydrogen, 20% CO2 gasses at 30psi. Cells were harvested by centrifugation, and DNA was isolated by phenol-chloroform and ethanol precipitation.