Sufficient intake of high amylose cornstarch maintains high colonic hydrogen production for 24 h in rats.

Colonic hydrogen (H) can suppress oxidative stress and damage in the body. We examined the minimum requirement of high amylose cornstarch (HAS) to maintain high colonic H production for 24 h. Ileorectostomized and sham-operated rats were fed a control diet supplemented with or without 20% HAS for 7 days. Colonic starch utilization was determined. Next, rats were fed the control diet with or without 10% or 20% HAS for 14 or 28 days, respectively. Breath and flatus H excretion for 24 h was measured. 1.04 g of resistant fraction in HAS was utilized for 24 h by colonic bacteria. High H excretion was not maintained for 24 h in rats fed the 10% HAS diet, from which only 0.89 g of resistant starch was estimated to be delivered. High colonic H production for 24 h would be maintained by delivering more HAS to the large intestine than is utilized.