Effect of resistant starch on fecal bulk and fermentation-dependent events in humans

Open Access
Publisher Website
Google Scholar
Abstract
This study investigated the effect of two diets, which differed in resistant starch (RS) concentration, on fecal bulk and fermentation-dependent events in 11 humans. Amounts of RS consumed were 5.0 +/- 0.4 and 39.0 +/- 3.0 g/d (mean +/- SEM) for the low- and high-RS diets, respectively. The two diets were fed for 3 wk each in a randomized crossover design. Fecal collections were made in the third week of each study period. The high-RS diet produced an increase (P < 0.01) in total fecal output (from 138 +/- 22 to 197 +/- 37 g/d) and lowered fecal pH (6.9 +/- 0.1 to 6.3 +/- 0.1). There were significant increases (P < 0.05) in the fecal concentrations and daily excretion of butyrate (+38% and +100%, respectively) and acetate (+26% and +72%, respectively) during the high-RS period. The fecal excretion (g/d) of nonstarch polysaccharides (NSP) also rose by 50% during the high-RS diet, suggesting that the presence of starch in the colon may affect the fermentation of NSP. Subjects reported an increase in flatulence and easier defecation. These results demonstrate that RS has a significant impact on putative markers of colonic health in humans.