Abstract 19393: Role of Gut Microbiota and Short Chain Fatty Acids in Modulating Energy Harvest and Fat Partitioning in Youth
Introduction: Evidence for a role of the gut microbiota in the development of human obesity has been provided, but the mechanisms underlying this association remain unknown.
Hypothesis: We hypothesize that gut microbiota promote fat accumulation in youth through the synthesis of short chain fatty acids (SCFA). In particular, in this study we aim at demonstrating that obese youth show a peculiar microbiome signature and that the degree of obesity is strongly associated with plasma levels of SCFA, which are the main product of carbohydrates oxidation from the gut flora. We also hypothesize that excessive production of SCFA can cause energy harvest by serving as substrates for hepatic de novo lipogenesis (DNL).
Methods: We analyzed the gut microbiota of 84 youth in whom body fat distribution was measured by fast-MRI, DNL quantitated using deuterated water, and the capability of gut flora to ferment CHO was assessed by 13C-fructose treatment in vitro.
Results: A significant association was found between the Firmicutes to Bacteroidetes ratio, and the abundance of Bacteroidetes and Actinobacteria with BMI, visceral and subcutaneous fat (all P <0.05). Plasma acetate, propionate and butyrate were associated with BMI and visceral and subcutaneous fat (all P<0.05) and with hepatic DNL (P=0.01, P=0.09, P=0.04, respectively). Moreover, the rate of CHO fermentation from the gut flora was higher in obese than in lean subjects (P=0.018).
Conclusions: These data demonstrate that obese youth show a different gut flora composition than lean and that SCFA are associated with body fat partitioning and DNL. Also, the gut flora of obese youth has a higher capability than the gut flora of lean to oxidize carbohydrates.
Author Disclosures: M. Goffredo: None. E. Parks: None. D. Wagner: None. K. Mass: None. J. Graf: None. N. Santoro: None.
- © 2016 by American Heart Association, Inc.