Abstract

Metabolomics Platform to Elucidate the Impact of Dietary Fiber in the Human Gut Metabolome Determined in vivo and in an in vitro Colon Simulator

Santosh Lamichhane, PhD Fellow, Aarhus University

Metabolomic analyses of feces are gaining increasing attention because gut microbial ecology and activity have vital role on human health and disease. Potential correlations between the fecal NMR-derived metabolome and the microbiota were elucidated in an in-vivo study. In combination with an in vitro study by a colon simulator, comprehensive dynamic biochemical changes of the human gut metabolome as function of treatment with polydextrose (PDX), an insoluble dietary fibre with prebiotic potential, were determined. A pronounced effect of PDX intake was seen on the NMR metabolite profiles of in-vivo and in-vitro derived feces. Intriguingly, correlation between the fecal metabolites and the levels of Bifidobacterium and Bacteroides could be established in the in-vivo study. On the other hand, multilevel data analysis enabled us to identify the specific inter-individual variations and fibre-induced response in the in-vitro derived fecal metabolome. Caprylic acid was identified to be the main marker of microbial diversity among the subjects. Beneficial metabolic effects of PDX were supported by increased levels of butyrate, acetate, N-acetyl compounds and lower levels of amino acids, branched chain fatty acids and trimethylamine Overall, our result demonstrates the usefulness of metabolomics to elucidate the impact of dietary fibres on the gut metabolome.