Retrograded high-amylose corn starch reduces cholic acid excretion from the small bowel in ileostomy subjects

To study the short-term effect of resistant starch (RS) from retrograded high-amylose corn starch (HACS) on the excretion of bile acids and nutrients from the small bowel in humans.

Seven healthy ileostomists were given a controlled, constant diet during three days. On days 2 and 3, 100 g/d of one of two test-products--drum-dried ordinary corn starch and autoclaved retrograded HACS, providing 5 and 39 g RS/d, respectively--was given, in random order. Ileostomy effluents were collected for 24 h per day and analysed for wet weight, dry weight, energy, bile acids and nutrients.

In-patient study at the metabolic ward, Department of Clinical Nutrition, Sahlgrenska University Hospital, Göteborg.

Consumption of retrograded HACS caused (1) a 42% lower mean excretion of cholic acid (P = 0.024); (2) a 42% lower mean wet weight concentration of bile acids (P < 0.001); (3) a 70% increased excretion of dry weight (P = 0.001); and (4) a 41% increased excretion of energy (P= 0.036) compared with consumption of drum-dried ordinary corn starch.

The reduced ileal excretion and concentration of cholic acid would be protective regarding colon cancer risk in addition to the increased fermentation substrate provided by RS and other energy-yielding components.