Project description:Opioid analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit long term use. In the current study using a chronic morphine-murine model a longitudinal approach was undertaken to investigate the role of morphine modulation of gut microbiome as a mechanism contributing to the negative consequences associated with opioids use. The results revealed a significant shift in the gut microbiome and metabolome within 24 hours following morphine treatment when compared to placebo. Morphine induced gut microbial dysbiosis exhibited distinct characteristic signatures profiles including significant increase in communities associated with pathogenic function, decrease in communities associated with stress tolerance. Collectively, these results reveal opioids-induced distinct alteration of gut microbiome, may contribute to opioids-induced pathogenesis. Therapeutics directed at these targets may prolong the efficacy long term opioid use with fewer side effects.
Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
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:Opioids analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit their use. It has been recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. Further study indicated distinct alterations in the gut microbiome and metabolome following morphine treatment, contributing to the negative consequences associated with opioid use. However, it is unclear how opioids modulate gut homeostasis in the context of a hospital acquired bacterial infection. In the current study, a mouse model of C. rodentium infection was used to investigate the role of morphine in the modulation of gut homeostasis in the context of a hospital acquired bacterial infection. Citrobacter rodentium is a natural mouse pathogen that models intestinal infection by enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) and causes attaching and effacing lesions and colonic hyperplasia. Morphine treatment resulted in 1) the promotion of C. rodentium systemic dissemination, 2) increase in virulence factors expression with C. rodentium colonization in intestinal contents, 3) altered gut microbiome, 4) damaged integrity of gut epithelial barrier function, 5) inhibition of C. rodentium-induced increase in goblet cells, and 6) dysregulated IL-17A immune response. This is the first study to demonstrate that morphine promotes pathogen dissemination in the context of intestinal C. rodentium infection, indicating morphine modulates virulence factor-mediated adhesion of pathogenic bacteria and induces disruption of mucosal host defense during C. rodentium intestinal infection in mice. This study demonstrates and further validates a positive correlation between opioid drug use/abuse and increased risk of infections, suggesting over-prescription of opioids may increase the risk in the emergence of pathogenic strains and should be used cautiously. Therapeutics directed at maintaining gut homeostasis during opioid use may reduce the comorbidities associated with opioid use for pain management.
Project description:Microbial colonization of the human gastrointestinal tract plays an important role in establishing health and homeostasis. However, the time-dependent and related functional signatures of microbial and human proteins during early colonization of the gut have yet to be determined. Thus, we employed shotgun proteomics via nano-2D-LC-MS/MS to simultaneously monitor microbial and human proteins in fecal samples from a healthy preterm infant during early development. ). All MS/MS spectra were searched against a predicted protein database containing 25 microbial species along with the Human RefSeq2011 genome using the SEQUEST algorithm (Eng et al, 1994), and filtered with DTASelect version 1.9 (Tabb et al, 2002) at the peptide level with standard filters [SEQUEST Xcorrs of at least 1.8 (+1), 2.5 (+2) 3.5 (+3)] organizing identified peptides to their corresponding protein sequences. This study provides the first elucidation of coordinated human and microbial proteins in the infant gut during early development.
Project description:The trillions of microorganisms in the human gastrointestinal tract are an underexplored aspect of pharmacology. Despite numerous examples of microbial effects on drug efficacy and toxicity, there is often an incomplete understanding of the underlying mechanisms. Here, we dissect the inactivation of the commonly prescribed cardiac glycoside, digoxin, by Eggerthella lenta. Whole genome transcriptional profiling, comparative genomics, and culture-based assays revealed a cytochrome-encoding operon up-regulated by digoxin, absent in non-metabolizing E. lenta strains, and predictive of the efficiency of digoxin inactivation by the human gut microbiome. Digoxin inactivation was further enhanced by microbial interactions and inhibited by arginine. Pharmacokinetic studies using gnotobiotic mice revealed that increasing dietary protein reduces the in vivo metabolism of digoxin by E. lenta, with significant changes to drug concentration in the urine and serum. These results emphasize the importance of viewing pharmacology from the perspective of both our human and microbial genomes. RNA-Seq analysis of Eggerthella lenta cultured with or without digoxin.