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.
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 analyzed the effects of antibiotics using a popular model of gut microbiota depletion in mice by a cocktail of antibiotics. We combined intestinal transcriptome together with metagenomic analysis of the gut microbiota to develop a new bioinformatics approach that probes the links between microbial components and host functions. We found that most antibiotic-induced alterations can be explained by three factors: depletion of the microbiota; direct effects of antibiotics on host tissues; and the effects of remaining antibiotic-resistant microbes. While microbe depletion led to down-regulation of immunity, the two other factors primarily inhibited mitochondrial gene expression and amounts of active mitochondria, and induced cell death. By reconstructing and analyzing a transkingdom network, we discovered that these toxic effects were mediated by virulence/quorum sensing in antibiotic-resistant bacteria. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
Project description:The gut microbiota plays an important role in host health. Microbiota dysbiosis has been implicated in the global epidemic of Metabolic Syndrome (MetS) and could impair host metabolism by noxious metabolites. It has been well established that the gut microbiota is shaped by host immune factors. However, the effect of T cells on the gut microbiota is yet unknown. Here, we performed a metagenomic whole-genome shotgun sequencing (mWGS) study of the microbiota of TCRb-/- mice, which lack alpha/beta T cells.
Project description:For identifying genes for sex determination in papaya, digital gene expression analysis by Ht-SuperSAGE (Matsumura et al., 2010) was carried out in flowers from male, female and hermaphrodite plants of papaya. Total more than 9,273,744 26bp-tags were obtained by sequence analysis using SOLiD3 and mapped on papaya primitive sex chromosome sequences.
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:We analyzed the effects of antibiotics using a popular model of gut microbiota depletion in mice by a cocktail of antibiotics. We combined intestinal transcriptome together with metagenomic analysis of the gut microbiota to develop a new bioinformatics approach that probes the links between microbial components and host functions. We found that most antibiotic-induced alterations can be explained by three factors: depletion of the microbiota; direct effects of antibiotics on host tissues; and the effects of remaining antibiotic-resistant microbes. While microbe depletion led to down-regulation of immunity, the two other factors primarily inhibited mitochondrial gene expression and amounts of active mitochondria, and induced cell death. By reconstructing and analyzing a transkingdom network, we discovered that these toxic effects were mediated by virulence/quorum sensing in antibiotic-resistant bacteria. This series includes gene expression of the laser microdissected compartments of the ileum such as villous epithelium, lamina propria and crypts from specific pathogen free mice common reference design with a pool of small intestine RNA labeled with Cy3
Project description:We analyzed the effects of antibiotics using a popular model of gut microbiota depletion in mice by a cocktail of antibiotics. We combined intestinal transcriptome together with metagenomic analysis of the gut microbiota to develop a new bioinformatics approach that probes the links between microbial components and host functions. We found that most antibiotic-induced alterations can be explained by three factors: depletion of the microbiota; direct effects of antibiotics on host tissues; and the effects of remaining antibiotic-resistant microbes. While microbe depletion led to down-regulation of immunity, the two other factors primarily inhibited mitochondrial gene expression and amounts of active mitochondria, and induced cell death. By reconstructing and analyzing a transkingdom network, we discovered that these toxic effects were mediated by virulence/quorum sensing in antibiotic-resistant bacteria. This series includes gene expression in the ileum of control, antibiotics (ABx)-treated, germfree, germfree-ABx-treated and mice colonized with normal or Abx-resistant microbiota. common reference design with a pool of small intestine RNA labeled with Cy3
Project description:This SuperSeries is composed of the SubSeries listed below. We analyzed the effects of antibiotics using a popular model of gut microbiota depletion in mice by a cocktail of antibiotics. We combined intestinal transcriptome together with metagenomic analysis of the gut microbiota to develop a new bioinformatics approach that probes the links between microbial components and host functions. We found that most antibiotic-induced alterations can be explained by three factors: depletion of the microbiota; direct effects of antibiotics on host tissues; and the effects of remaining antibiotic-resistant microbes. While microbe depletion led to down-regulation of immunity, the two other factors primarily inhibited mitochondrial gene expression and amounts of active mitochondria, and induced cell death. By reconstructing and analyzing a transkingdom network, we discovered that these toxic effects were mediated by virulence/quorum sensing in antibiotic-resistant bacteria.
Project description:This study aims to understand the systemic component of psoriasis pathogenesis since psoriasis patients have higher risk of developing diesases beyond skin inflammation. In this study, we collected sigmoidal gut biopsies to profile host transcriptomic changes associated with psoriasis patients and healthy subjects. This exepriment provided transcriptomic dataset of host response and is integrated with fecal metagenomic data and flow cytometry dataset as part of the multi-omic study.