Integrating multiple analytical datasets to compare metabolite profiles of mouse colonic-cecal contents and feces

Authors: Zeng, Huawei; GRAPOV, DMITRY - National Institutes Of Health (NIH); FAHRMANN, JOHANNES - National Institutes Of Health (NIH); FIEHN, OLIVER - National Institutes Of Health (NIH); Combs, Gerald

Submitted to: Metabolites
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/6/2015
Publication Date: 9/11/2015
Publication URL: http://handle.nal.usda.gov/10113/62643
Citation: Zeng, H., Grapov, D., Fahrmann, J., Fiehn, O., Combs, G.F. 2015. Integrating multiple analytical datasets to compare metabolite profiles of mouse colonic-cecal contents and feces. Metabolites. 5:489-501.

Interpretive Summary: The gastrointestinal tract, which is the site of the host’s first encounter with nutrients, microorganisms and other bioactive factors in foods, hosts a complex community of microorganisms. The role of that community in affecting health is becoming increasingly evident. Research has shown that differences in the nature of the gut bacteria are associated with risk to obesity, colon cancer and type 2 diabetes mellitus. Such effects would appear to involve the production by the gut bacteria, which can be used as substrates and/or signaling molecules by mucosal epithelial cells. However, little is presently known about the metabolic phenotypes of the gut bacteria nor whether those can be estimated by analyzing feces, a more readily accessible specimen, particularly in clinical contexts. Therefore, we compared the metabolic profiles of the colonic-cecal luminal contents feces of a mouse experimental model fed a standard chow-type diet. In the present study, we detected a total of 270 low molecular weight compounds in colonic-cecal contents and feces, which is the first characterization of relationships among metabolites present in the colonic-cecal contents and feces in a healthy mouse model. These data will be useful for scientists who are interested in the development of non-invasive biomarkers.

Technical Abstract: The pattern of metabolites produced by the gut microbiome comprises a phenotype indicative of the means by which that microbiome affects the gut. We characterized that phenotype in mice by conducting metabolomic analyses of the colonic-cecal contents, comparing that to the metabolite patterns of feces in order to determine the suitability of fecal specimens as proxies for assessing the metabolic impact of the gut microbiome. We detected a total of 270 low molecular weight metabolites in colonic-cecal contents and feces by gas chromatograph, time-of-flight mass spectrometry (GC-TOF) and ultra-high performance liquid chromatography, quadrapole time- of-flight mass spectrometry (UPLC-Q-TOF). Of that number, 251 (93%) were present in both types of specimen, representing almost all known biochemical pathways related to the amino acid, carbohydrate, energy, lipid, membrane transport, nucleotide, genetic information processing, and cancer-related metabolism. A total of 115 metabolites differed significantly in relative abundance between both colonic-cecal contents and feces. There data comprise the first characterization of relationships among metabolites present in the colonic-cecal contents and feces in a healthy mouse model, and shows that feces can be a useful proxy for assessing the pattern of metabolites to which the colonic mucosum is exposed.