Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary transcription profiling data from the mouse hosts have also been deposited at ArrayExpress under accession number E-MTAB-3590 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3590/ ).
Project description:Here we report 16S rRNA data in gut microbiota of autism spectrum disorders compared with healthy volunteers. A total of 1322 operational taxonomic units (OTUs) were identified in the sequence data. The Bacteroidetes and Firmicutes were both dominated phylum in ausitic subjects and healthy controls. Phylum level analysis showed a clear alteration of the bacterial gut community in ASD characterized by a higher Firmicutes (P < 0.05), Proteobacteria (P < 0.001), and Actinobacteria (P < 0.001) than that in healthy controls. However, Bacteroidetes were significantly decreased in ASD patients (P < 0.001).
Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary RNA-seq and DNA-seq data sets of the microbiome from this study have also been deposited at ArrayExpress under accession number E-MTAB-3562 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3562/ ).
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:HIV is known to severely affect the gastrointestinal immune system, in particular compartments of immunity that regulate gut microbial composition. Furthermore, recent studies in mice have shown that dysregulation of the gut microbiome can contribute to chronic inflammation, which is a hallmark of HIV and is thought to fuel disease progression. We sought to understand whether the gut microbial community differs in HIV-infected subjects, and whether such putative differences are associated with disease progression. We found that dysbiosis in the gut mucosally-adherent bacterial community associates with markers of chronic inflammation and disease progression in HIV-infected subjects, and this dysbiosis remains in many subjects undergiong antiretroviral therapy.
Project description:HIV is known to severely affect the gastrointestinal immune system, in particular compartments of immunity that regulate gut microbial composition. Furthermore, recent studies in mice have shown that dysregulation of the gut microbiome can contribute to chronic inflammation, which is a hallmark of HIV and is thought to fuel disease progression. We sought to understand whether the gut microbial community differs in HIV-infected subjects, and whether such putative differences are associated with disease progression. We found that dysbiosis in the gut mucosally-adherent bacterial community associates with markers of chronic inflammation and disease progression in HIV-infected subjects, and this dysbiosis remains in many subjects undergiong antiretroviral therapy. We used G3 PhyloChip microarrays (commercially available from Second Genome, Inc.) to profile gut bacteria in rectosigmoid biopsies from 32 subjects: 6 HIV-infected viremic untreated (VU), 18 HIV-infected subjects on highly active antiretroviral therapy (HAART), 1 HIV-infected long-term non-progressor that is untreated (LTNP), and 9 HIV-uninfected subjects (HIV-).