898-P: Colonic Acetate Production in Youth with and without Obesity

Abstract

Recent studies suggest that gut microbiota can modulate body weight via products of bacterial fermentation. We tested the hypothesis that, for the same amount of fermentable carbohydrate, lean and obese youth have a different capability to produce acetate in the colon. We also tested the effect of colonic fermentation on plasma glucose, insulin, C-peptide, and free fatty acids (FFA). 38 youth, ages 15 to 21 yr (19 lean/19 obese) underwent a 10-hour sodium [d3]-acetate intravenous infusion to determine the rate of appearance of acetate (Ra) in plasma before and after 20g of lactulose (per os). Pre- and post- Ra values were determined at a quasi-steady state. Compared to obese youth, lean showed a larger increase in Ra after colonic fermentation (P=0.001). Plasma FFA concentrations declined from 0 to 300 minutes (nadir), with a greater reduction in lean youth (P=0.042). Insulin, glucose, and C-peptide levels were lower at the end of the study than at baseline in both groups (all P 0.05). These data suggest that 1) obese youth either ferment lactulose to a lesser degree or experience a higher hepatic uptake of acetate; 2) acetate may cause a reduction in FFA during the fasting state that is more marked in lean youth; 3) acetate may be associated with changes in glucose metabolism, although herein, it is difficult to differentiate between the effect of acetate infusion and prolonged fasting. Disclosure B. Galuppo: None. G. Cline: None. M. A. Van name: None. C. Agazzi: None. C. L. Kien: None. N. Santoro: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK114504)