Project description:BACKGROUND: The intestinal microbiota play a key role in the onset, progression, and recurrence of Crohn’s disease (CD). Most microbiome studies assay fecal material, which does not provide region-specific information on mucosally adherent bacteria that directly interact with host systems. Changes in luminal oxygen has been proposed as a contributor to CD dybiosis. METHODS: 16S rRNA data was generated using colonic and ileal mucosal from patients with CD and without inflammatory bowel diseases (nonIBD). We developed profiles reflecting bacterial abundance within defined aerotolerance categories. Bacterial diversity, composition, and aerotolerance profiles were compared across intestinal regions and disease phenotypes. RESULTS: Bacterial diversity decreased in CD in both ileum and colon. Aerotolerance profiles significantly differed between intestinal segments in nonIBD, though both were dominated by obligate anaerobes, as expected. In CD, high relative levels of obligate anaerobes were maintained in the colon and increased in the ileum. Relative abundance of similar and distinct taxa were altered in colon and ileum. Notably, several obligate anaerobes, such as Bacteroides fragilis, dramatically increased in CD in one or both intestinal segments, though specific increasing taxa varied across patients. Increased abundance of taxa from the Proteobacteria phylum was found only in the ileum. Bacterial diversity was significantly reduced in resected pre-operative tissues of patients that developed disease recurrence across two independent cohorts, with common lower abundance of bacteria from the Bacteroides, Streptococcus, and Blautia genera. CONCLUSIONS: Mucosally adherent bacteria in colon and ileum show distinct alterations in CD that provide additional insights not revealed in fecal material.
2020-04-15 | GSE147600 | GEO
Project description:16S rRNA-Seq of Mus musculus: fecal sample
Project description:The impact of mono-chronic S. stercoralis infection on the gut microbiome and microbial activities in infected participants was explored. The 16S rRNA gene sequencing of a longitudinal study with 2 sets of human fecal was investigated. Set A, 42 samples were matched, and divided equally into positive (Pos) and negative (Neg) for S. stercoralis diagnoses. Set B, 20 samples of the same participant in before (Ss+PreT) and after (Ss+PostT) treatment was subjected for 16S rRNA sequences and LC-MS/MS to explore the effect of anti-helminthic treatment on microbiome proteomes.
Project description:The community composition (in terms of abundance, distribution and contribution of diverse clades) of bacteria involved in nitrogen transformations in the oxygen minimum zones may be related to the rates of fixed N loss in these systems. The abundance of both denirifying and anammox bacteria, and the assemblage composition of denitrifying bacteria were investigated in the Eastern Tropical South Pacific and the Arabian Sea using assays based on molecular markers for the two groups of bacteria. The abundance and distribution of bacteria associated with the fixed N removal processes denitrification and anammox were investigated using quantitative PCR for genes encoding nitrite reductase (nirK and nirS) in denitrifying bacteria and hydrazine oxidase(hzo) and 16S rRNA genesin anammox bacteria. All of these genes had depth distributions with maxima associated with the secondary nitrite maximum in low oxygen waters. NirS was mch more abundant than nirK, and much more abundant than the 16S rRNA gene from anammox bacteria. The ratio of hzo:16S rRNA for anammox was low and variable implying greater unexplored diversity in the the hzo gene. Assemblage composition of the abundant nirS-type denitrifiers was evaluated using a funcitonal gene microarray. Of the nirS archetypes represented on the microarray, very few occurred speficically in one region or depth interval, but the assemblages varied significantly. Community composition of denitrifiers based on microarray analysis of the nirS gene was most different between geographical regions. Within each region, the surface layer and OMZ assemblages clustered distinctly. Thus, in addition to spatial and temporal variation in denitrificaiton and anammox rates, both microbial abundance and community composition also vary between OMZ regions and depths. Two color array (Cy3 and Cy5): the universal standard 20-mer oligo is printed to the slide with a 70-mer oligo (an archetype). Environmental DNA sequences (fluoresced with Cy3) within 15% of the 70-mer conjugated to a 20-mer oligo (fluoresced with Cy5) complementary to the universal standard will bind to the oligo probes on the array. Signal is the ratio of Cy3 to Cy5. Three replicate probes were printed for each archetype. Two replicate arrays were run on duplicate targets.
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.
Project description:The community composition (in terms of abundance, distribution and contribution of diverse clades) of bacteria involved in nitrogen transformations in the oxygen minimum zones may be related to the rates of fixed N loss in these systems. The abundance of both denirifying and anammox bacteria, and the assemblage composition of denitrifying bacteria were investigated in the Eastern Tropical South Pacific and the Arabian Sea using assays based on molecular markers for the two groups of bacteria. The abundance and distribution of bacteria associated with the fixed N removal processes denitrification and anammox were investigated using quantitative PCR for genes encoding nitrite reductase (nirK and nirS) in denitrifying bacteria and hydrazine oxidase(hzo) and 16S rRNA genesin anammox bacteria. All of these genes had depth distributions with maxima associated with the secondary nitrite maximum in low oxygen waters. NirS was mch more abundant than nirK, and much more abundant than the 16S rRNA gene from anammox bacteria. The ratio of hzo:16S rRNA for anammox was low and variable implying greater unexplored diversity in the the hzo gene. Assemblage composition of the abundant nirS-type denitrifiers was evaluated using a funcitonal gene microarray. Of the nirS archetypes represented on the microarray, very few occurred speficically in one region or depth interval, but the assemblages varied significantly. Community composition of denitrifiers based on microarray analysis of the nirS gene was most different between geographical regions. Within each region, the surface layer and OMZ assemblages clustered distinctly. Thus, in addition to spatial and temporal variation in denitrificaiton and anammox rates, both microbial abundance and community composition also vary between OMZ regions and depths.
Project description:We found that mainstream cigarette smoking (4 cigarettes/day, 5 days/week for 2 weeks using Kentucky Research Cigarettes 3R4F) resulted in >20% decrease in the percentage of normal Paneth cell population in Atg16l1 T300A mice but showed minimal effect in wildtype littermate control mice, indicating that Atg16l1 T300A polymorphism confers sensitivity to cigarette smoking-induced Paneth cell damage. We performed 16S rRNA sequencing to identify potential microbiota changes associated with Paneth cell defect in Atg16l1 T300A mice exposed to cigarette smoking. Female mice were used at 4-5 weeks of age. Cigarette smoking was performed using smoking chamber with the dosage and schedule as described above. The fecal samples from the mice were collected for 16S rRNA sequencing analysis after completing 6 weeks of smoking.
Project description:A three-stage continuous fermentative system was developed to simulate and control physicochemical factors of the gut biology. Inoculation was of each reactor was performed from a human fecal sample which was initially amplified with a batch procedure. Samples from the initial feces, the batch and from the bioreactors media were collected to extract bacterial DNA. 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray. A 5 chip study was realized, each corresponding to hybridization with 250ng of labelled 16S rRNA gene amplicons from either the initial stool, the batch inoculum or fermentative medium different compartments of the simulated colon (Proximal, Transversal and Distal). Each probe (4441) was synthetized in three replicates.