Excretion of starch and esterified short-chain fatty acids by ileostomy subjects after the ingestion of acylated starches

Background: Short-chain fatty acids (SCFAs) have a role in maintaining bowel health and can assist in the prevention and treatment of colonic disease. The ability of acylated starches to deliver SCFAs to the larae bowel has been shown in animal studies but has not been established in humans. Objective: The aim was to determine whether cooked, highly acylated starches were resistant to small intestinal digestion in ileostomy volunteers. Design: Volunteers consumed single doses of custards containing 20 cooked acetylated, propionylated, or butyrylated high-amylose maize starches (HAMSA, HAMSP, and HAMSB, respectively) on each collection day. The amounts of starch and of esterified SCFAs ingested and subsequently excreted in the stoma effluent were measured. Custards containing unacylated high-amylose maize starch (Hylon VII, HAMS) and low-amylose maize starch (3401 C, LAMS) were consumed as controls. Results: Between 73% and 76% of the esterified SCFAs survived small intestinal digestion, which showed the potential of acylated starches to deliver specific SCFAs to the large bowel. The resistance of starches to small intestinal digestion as measured by ileal excretion was significantly greater for HAMSA, HAMSP, HAMSB, and HAMS than for LAMS (P < 0.001). The concentration of acetate in stoma digesta was higher than expected in all groups; this additional acid may have been derived from endogenous sources. Conclusions: Acylated starches are a potentially effective method of delivering significant quantities of specific SCFAs to the colon in humans. These products have potential application in the treatment and prevention of bowel disorders amenable to modulation by SCFAs.