Effect of Short-chain Fatty Acids on Aerobic Endurance

Randomized, double-blind, placebo-controlled crossover study designed to determine the effects of increasing colonic short-chain fatty acid (SCFA) content on aerobic endurance in healthy adults, and to identify underpinning mechanisms. In random order, healthy physically active adults will consume provided diets low in fiber and supplemented with SCFA-enriched high amylose maize starch (a poorly digested resistant starch considered a fermentable fiber) or low amylose maize starch (a rapidly digestible starch) for 1-week separated by a ≥2-week washout. At the end of each intervention period, participants will complete an endurance exercise bout followed by a time trial. Biological samples will be collected to assess muscle and whole body metabolism, gut microbiota, inflammation, and gastrointestinal function.