Impact of Extreme Obesity and Diet-Induced Weight Loss on the Fecal Metabolome and Gut Microbiota.

SCOPE A limited number of human studies have characterized the fecal microbiota and metabolome in extreme obesity and after diet-induced weight loss. METHODS AND RESULTS Fecal samples from normal-weight and extremely obese adults and from obese participants before and after moderate diet-induced weight loss were evaluated for their interaction with the intestinal adenocarcinoma cell line HT29 using an impedance-based in vitro model, which revealed variations in the interaction between the gut microbiota and host linked to obesity status. Microbiota composition, short chain fatty acids and other intestinal metabolites were further analyzed to assess the interplay among diet, gut microbiota and host in extreme obesity. Microbiota profiles were distinct between normal-weight and obese participants and were accompanied by fecal signatures in the metabolism of biliary compounds and catecholamines. Moderate diet-induced weight loss promoted shifts in the gut microbiota, and the primary fecal metabolomics features were associated with diet and the gut-liver and gut-brain axes. CONCLUSIONS Analyses of the fecal microbiota and metabolome enable assessment of the impact of diet on gut microbiota composition and activity, supporting the potential use of certain fecal metabolites or members of the gut microbiota as biomarkers for the efficacy of weight loss in extreme obesity. This article is protected by copyright. All rights reserved.