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: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:Objectives: Obstructive Sleep Apnea (OSA) is related to repeated upper airway collapse, intermittent hypoxia, and intestinal barrier dysfunction. The resulting damage to the intestinal barrier may affect or be affected by the intestinal microbiota. Methods: A prospective case-control was used, including 48 subjects from Sleep Medicine Center of Nanfang Hospital. Sleep apnea was diagnosed by overnight polysomnography. Fecal samples and blood samples were collected from subjects to detect intestinal microbiome composition (by 16S rDNA gene amplification and sequencing) and intestinal barrier biomarkers – intestinal fatty acid-binding protein (I-FABP) and D-lactic acid (D-LA) (by ELISA and colorimetry, respectively). Results: The severity of OSA was related to differences in the structure and composition of the intestinal microbiome. Enriched Fusobacterium, Megamonasa, Lachnospiraceae_UCG_006, and reduced Anaerostipes was found in patients with severe OSA. Enriched Ruminococcus_2, Lachnoclostridium, Lachnospiraceae_UCG_006, and Alloprevotella was found in patients with high intestinal barrier biomarkers. Lachnoclostridium and Lachnospiraceae_UCG_006 were the common dominant bacteria of OSA and intestinal barrier damage. Fusobacterium and Peptoclostridium was independently associated with apnea-hypopnea index (AHI). The dominant genera of severe OSA were also related to glucose, lipid, neutrophils, monocytes and BMI. Network analysis identified links between the intestinal microbiome, intestinal barrier biomarkers, and AHI. Conclusions: The study confirms that changes in the intestinal microbiota are related to intestinal barrier biomarkers among patients in OSA. These changes may play a pathophysiological role in the systemic inflammation and metabolic comorbidities associated with OSA, leading to multi-organ morbidity of OSA.
Project description:IL-17 and IL-17R signaling in the intestinal epithelium regulate the intestinal microbiome. Given the reported links between intestinal dysbiosis, bacterial translocation, and liver disease, we hypothesized that intestinal IL-17R signaling plays a critical role in mitigating hepatic inflammation. To test this, we studied intestinal epithelial-specific IL-17RA deficient mice in a model of concanavalin A hepatitis. Absence of enteric IL-17RA signaling exacerbated hepatitis and hepatocyte cell death. These mice exhibited commensal dysbiosis, increased intestinal and liver Il18, and increased liver translocation of bacterial products, specifically CpG DNA. Mechanistically, CpG DNA induced hepatic IL-18, increasing IFNγ and FasL in hepatic T-cells to drive inflammation. Thus, intestinal IL-17R regulates translocation of TLR9 ligands and constrains susceptibility to hepatitis. These data connect enteric Th17 signaling and the microbiome in hepatitis, with broader implications on the effects of impaired intestinal immunity and subsequent release of microbial products seen in other extra-intestinal pathologies.
Project description:16S metagenomic analysis has provided much information about the intestinal microbiome. However, there are no reports that describe their appropriate taxonomic classification rank. Moreover, studies differ on the taxonomic ranking of the same microorganism. Intestinal microbiome exerts a significant degree of influence on the host via the metabolome. In the present study, we searched for their appropriate classification ranks based on the correlation between the metabolome and microbiome. Over 200 metabolites were identified by capillary electrophoresis and time-of-flight mass spectrometry (CE-TOFMS) based metabolomics of faeces from antibiotics-treated and untreated mice. Nine phyla, 15 orders, 22 classes, 40 families, and 59 genera were identified by 16S metagenomic analysis. Principle component analysis (PCA) of the intestinal microbiome at each taxonomic rank revealed differences between the antibiotic-treated and untreated groups on the first principle component in the family and genus-level analyses. These differences were similar to those found in the metabolome PCA. In addition, a strong correlation between principle component score of the metabolome and that of the microbiome was observed in the case of family and genus-level analyses. From these results, we hypothesize that lower taxonomic ranks such as family or genus are preferable while using 16S metagenome analysis for investigating the crosstalk, via metabolites, between intestinal microbiome and the host.
Project description:The intestinal microbiome was examined from fecal pellets of animals with genetic targeting of the BTLA inhibitory receptor and the TNFR superfamily member HVEM, or in animals treated with agonist antibodies specific for BTLA.
Project description:Evaluation of short-read-only, long-read-only, and hybrid assembly approaches on metagenomic samples demonstrating how they affect gene and protein prediction which is relevant for downstream functional analyses. For a human gut microbiome sample, we use complementary metatranscriptomic, and metaproteomic data to evaluate the metagenomic-based protein predictions.
Project description:With annually 2.56 million deaths worldwide, pneumonia is one of the leading causes of death. Most frequent causative pathogens are Streptococcus pneumoniae and influenza A virus. Lately, the interaction between pathogens, the host and its microbiome gained more attention. A healthy microbiome is known to enhance the immune response towards pathogens, however, our knowledge on how infections affect the microbiome is still scarce. In this study, a meta-omics approach was used to investigate the impact of S. pneumoniae and influenza A virus infection on structure and function of the respiratory and gastrointestinal microbiomes of mice. In particular, the taxonomic composition of the respiratory microbiome was less affected by bacterial colonization and viral infection compared to S. pneumoniae infection. Pneumococcal pneumonia led to reduction of bacterial families and lower diversity in the respiratory microbiome, whereas diversity/richness was unaffected following H1N1 infection. Within the gastrointestinal microbiome we found exclusive changes in structure and function depending on the pneumonia inducing pathogen. Exemplarily, increased abundance of Akkermansiaceae and Spirochaetaceae, as well as decreased amounts of Clostridiaceae in response to S. pneumoniae infection, while increased presence of Enterococcaceae and Staphylococcaceae was specific for viral-induced pneumonia. Investigation of the intestinal microbiomes functional composition revealed reduced expression of flagellin and rubrerythrin and increased levels of ATPase during pneumococcal infection, while increased amounts of acetyl-CoA acetyltransferase and, enoyl-CoA transferase were unique after H1N1 infection. The identification of specific taxonomical and functional profiles during infection with a respective pathogen could deliver new insights in the role of the microbiome during disease and be beneficial for discrimination of pneumococcal- or viral-induced pneumonia.
Project description:With annually 2.56 million deaths worldwide, pneumonia is one of the leading causes of death. Most frequent causative pathogens are Streptococcus pneumoniae and influenza A virus. Lately, the interaction between pathogens, the host and its microbiome gained more attention. A healthy microbiome is known to enhance the immune response towards pathogens, however, our knowledge on how infections affect the microbiome is still scarce. In this study, a meta-omics approach was used to investigate the impact of S. pneumoniae and influenza A virus infection on structure and function of the respiratory and gastrointestinal microbiomes of mice. In particular, the taxonomic composition of the respiratory microbiome was less affected by bacterial colonization and viral infection compared to S. pneumoniae infection. Pneumococcal pneumonia led to reduction of bacterial families and lower diversity in the respiratory microbiome, whereas diversity/richness was unaffected following H1N1 infection. Within the gastrointestinal microbiome we found exclusive changes in structure and function depending on the pneumonia inducing pathogen. Exemplarily, increased abundance of Akkermansiaceae and Spirochaetaceae, as well as decreased amounts of Clostridiaceae in response to S. pneumoniae infection, while increased presence of Enterococcaceae and Staphylococcaceae was specific for viral-induced pneumonia. Investigation of the intestinal microbiomes functional composition revealed reduced expression of flagellin and rubrerythrin and increased levels of ATPase during pneumococcal infection, while increased amounts of acetyl-CoA acetyltransferase and, enoyl-CoA transferase were unique after H1N1 infection. The identification of specific taxonomical and functional profiles during infection with a respective pathogen could deliver new insights in the role of the microbiome during disease and be beneficial for discrimination of pneumococcal- or viral-induced pneumonia.