Project description:5 human fecal gut samples, collected and prepared for standard MudPIT data collection from healthy volunteers, searched with the ComPIL database. x3 replicates each
Project description:A metaproteomics analysis was conducted on the infant fecal microbiome to characterize global protein expression in 8 samples obtained from infants with a range of early-life experiences. Samples included breast-, formula- or mixed-fed, mode of delivery, and antibiotic treatment and one set of monozygotic twins. Although label-free mass spectrometry-based proteomics is routinely used for the identification and quantification of thousands of proteins in complex samples, the metaproteomic analysis of the gut microbiome presents particular technical challenges. Among them: the extreme complexity and dynamic range of member taxa/species, the need for matched, well-annotated metagenomics databases, and the high inter-protein sequence redundancy/similarity between related members. In this study, a metaproteomic approach was developed for assessment of the biological phenotype and functioning, as a complement to 16S rRNA sequencing analysis to identify constituent taxa. A sample preparation method was developed for recovery and lysis of bacterial cells, followed by trypsin digestion, and pre-fractionation using Strong Cation Exchange chromatography. Samples were then subjected to high performance LC-MS/MS. Data was searched against the Human Microbiome Project database, and a homology-based meta-clustering strategy was used to combine peptides from multiple species into representative proteins. Bacterial taxonomies were also identified, based on species-specific protein sequences, and protein metaclusters were assigned to pathways and functional groups. The results obtained demonstrate the applicability of this approach for performing qualitative comparisons of human fecal microbiome composition, physiology and metabolism, and also provided a more detailed assessment of microbial composition in comparison to 16S rRNA.
Project description:Background and aims: Gene mutations or variants leading to insufficient reactive oxygen species (ROS) production have been associated with inflammatory bowel disease (IBD). In particular, 40-50% of patients with chronic granulomatous disease have IBD (CGD-IBD). CGD is caused by inherited defects in any one of the 5 subunits forming the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex 2 (NOX2), leading to severely reduced or absent phagocyte-derived ROS production. While conventional IBD therapies can treat CGD-IBD, their benefits must be weighed against the risk of infection in this immune compromised population. Understanding the impact of NOX2 defects on the composition and function of the intestinal microbiota may lead to the identification of treatments for CGD-IBD. Methods: We evaluated GI symptom and quality of life scores, and clinical biomarkers of local (i.e. fecal occult blood and calprotectin) and systemic (i.e. CBC, CRP, ESR, and albumin) inflammation in a cohort of 79 patients with CGD, 8 mutation carriers and 17 healthy controls followed at the National Institutes of Health (NIH). We profiled the intestinal microbiome by 16S rRNA (V4 region) sequencing and the stool metabolome by mass spectrometry in all fecal samples, and further validated our findings by profiling the stool microbiome in a second cohort of 36 patients with CGD recruited from 11 centers across North-America through the Primary Immune Deficiency Treatment Consortium (PIDTC). Predictive functional profiling of the microbial communities based on 16S rRNA sequencing was also performed. Results: After controlling for significant variables, we show decreased alpha diversity and identified distinct intestinal microbiome and metabolomic profiles in patients with CGD compared to healthy individuals. In particular, we observed enrichment for Erysipelatoclostridium spp., Sellimonas spp. and Lachnoclostridium spp. in stool samples from patients with CGD. Despite differences in alpha and beta diversity in samples from the NIH compared to the PIDTC cohort, there were several bacterial taxa that correlated significantly between both cohorts. We further demonstrate that patients with active IBD and/or a history of IBD have a distinct microbiome and metabolomic profile compared to patients without CGD-IBD and identified bacterial taxa to be evaluated as potential markers of disease severity, as well as targets for future therapeutic interventions. Conclusions: Intestinal microbiome and metabolomic signatures distinguished patients with CGD and CGD-IBD and identified microbial and metabolomic candidates to be further evaluated as potential targets to improve the management of patients with CGD-IBD.
Project description:The aim of this study was to test the hypothesis that replenishing the microbiota with a fecal microbiota transplant (FMT) can rescue a host from an advanced stage of sepsis. We developed a clinically-relevant mouse model of lethal polymicrobial gut-derived sepsis in mice using a 4-member pathogen community (Candida albicans, Klebsiella oxytoca, Serratia marcescens, Enterococcus faecalis) isolated from a critically ill patient. In order to mimic pre-operative surgical patient condition mice were exposed to food restriction and antibiotics. Approximately 18 hours prior to surgery food was removed from the cages and the mice were allowed only tap water. Each mouse received an intramuscular Cefoxitin injection 30 minutes prior to the incision at a concentration of 25 mg/kg into the left thigh. Mice were then subjected to a midline laparotomy, 30% hepatectomy of the left lateral lobe of the liver and a direct cecal inoculation of 200 µL of the four pathogen community. On postoperative day one, the mice were administered rectal enema. Mice were given either 1 ml of fecal microbiota transplant (FMT) or an autoclaved control (AC). This was again repeated on postoperative day two. Mice were then followed for mortality. Chow was restored to the cages on postoperative day two, approximately 45 hours after the operation. The injection of fecal microbiota transplant by enema significantly protected mice survival, reversed the composition of gut microflora and down-regulated the host inflammatory response. The cecum, left lobe of the liver, and spleen were isolated from mice for microarray processing with three or more replicates for six expermental conditions: non-treated control, SAHC POD1, SAHC.AC POD2, SAHC.FMT POD2, SAHC.AC POD7, SAHC.FMT POD7
Project description:Trypanosoma cruzi parasites are the causative agents of Chagas disease. These parasites infect cardiac and gastrointestinal tissues, leading to local inflammation and tissue damage. Digestive Chagas disease is associated with perturbations in food absorption, intestinal traffic and defecation. However, the impact of T. cruzi infection on the gut microbiota and metabolome have yet to be characterized. In this study, we applied mass spectrometry-based metabolomics and 16S rRNA sequencing to profile infection-associated alterations in fecal bacterial composition and fecal metabolome through the acute-stage and into the chronic stage of infection, in a murine model of Chagas disease. We observed joint microbial and chemical perturbations associated with T. cruzi infection. These included alterations in conjugated linoleic acid (CLA) derivatives and in specific members of families Ruminococcaceae and Lachnospiraceae, as well as alterations in secondary bile acids and members of order Clostridiales. These results highlight the importance of multi-'omics' and poly-microbial studies in understanding parasitic diseases in general, and Chagas disease in particular.
Project description:The human gut microbiome plays a key role in human health 1 , but 16S characterization lacks quantitative functional annotation 2 . The fecal metabolome provides a functional readout of microbial activity and can be used as an intermediate phenotype mediating host-microbiome interactions 3 . In this comprehensive description of the fecal metabolome, examining 1,116 metabolites from 786 individuals from a population-based twin study (TwinsUK), the fecal metabolome was found to be only modestly influenced by host genetics (heritability (H2) = 17.9%). One replicated locus at the NAT2 gene was associated with fecal metabolic traits. The fecal metabolome largely reflects gut microbial composition, explaining on average 67.7% (±18.8%) of its variance. It is strongly associated with visceral-fat mass, thereby illustrating potential mechanisms underlying the well-established microbial influence on abdominal obesity. Fecal metabolic profiling thus is a novel tool to explore links among microbiome composition, host phenotypes, and heritable complex traits.
Project description:BACKGROUNDThere has been a striking generational increase in the prevalence of food allergies. We have proposed that this increase can be explained, in part, by alterations in the commensal microbiome.METHODSTo identify bacterial signatures and metabolic pathways that may influence the expression of this disease, we collected fecal samples from a unique, well-controlled cohort of twins concordant or discordant for food allergy. Samples were analyzed by integrating 16S rRNA gene amplicon sequencing and liquid chromatography-tandem mass spectrometry metabolite profiling.RESULTSA bacterial signature of 64 operational taxonomic units (OTUs) distinguished healthy from allergic twins; the OTUs enriched in the healthy twins were largely taxa from the Clostridia class. We detected significant enrichment in distinct metabolite pathways in each group. The enrichment of diacylglycerol in healthy twins is of particular interest for its potential as a readily measurable fecal biomarker of health. In addition, an integrated microbial-metabolomic analysis identified a significant association between healthy twins and Phascolarctobacterium faecium and Ruminococcus bromii, suggesting new possibilities for the development of live microbiome-modulating biotherapeutics.CONCLUSIONTwin pairs exhibited significant differences in their fecal microbiomes and metabolomes through adulthood, suggesting that the gut microbiota may play a protective role in patients with food allergies beyond the infant stage.TRIAL REGISTRATIONParticipants in this study were recruited as part of an observational study (ClinicalTrials.gov NCT01613885) at multiple sites from 2014 to 2018.FUNDINGThis work was supported by the Sunshine Charitable Foundation; the Moss Family Foundation; the National Institute of Allergy and Infectious Diseases (NIAID) (R56AI134923 and R01AI 140134); the Sean N. Parker Center for Allergy and Asthma Research; the National Heart, Lung, and Blood Institute (R01 HL 118612); the Orsak family; the Kepner family; and the Stanford Institute for Immunity, Transplant and Infection.