Short-Chain Fatty Acid Fermentation Products of Plant Fiber Affect Glucose Metabolism of Isolated Rat Hepatocytes

Short-chain fatty acids (SCFA) produced during fermentation of plant fibers and absorbed from the colon may affect hepatic glucose metabolism. We examined the effects of different fatty acids on rates of glucose production and glycolysis in isolated rat hepatocytes. Acetate, butyrate, and long-chain fatty acids significantly increased glucose production from lactate. However, propionate and valerate significantly decreased glucose production from lactate. Whereas 5 mM butyrate increased the incorporation of [14C]lactate into [14C]glucose by 80%, 5 mM propionate produced a 67% decrease. Glycolysis was significantly decreased by acetate, butyrate, and long-chain fatty acids. However, propionate and valerate significantly increased glycolysis. Thus propionate, which inhibits hepatic acetate metabolism, acts to increase glucose use and decrease glucose production. Plant fibers may influence hepatic glucose metabolism via their SCFA metabolites.