Effect of resistant starch on breath-hydrogen and methane excretion in healthy volunteers.

Colonic fermentation of dietary carbohydrates and fiber might produce a protective effect against the development of large bowel cancer. Resistant starch, ie, starch that escapes small bowel digestion, is a candidate fermentable substrate that has been hitherto little studied. We supplemented 19 healthy volunteers with 15 g native amylomaize (Hylon-VII) three times a day, containing 28 g type II resistant starch, or with dextrins as a placebo for 7 d in a crossover design. Pre-experimentally, 11 subjects regularly produced breath methane and 8 did not. Resistant starch increased 24-h integrated excretion of breath hydrogen. The mean rise relative to placebo was 35% (P = 0.03) for all subjects and 60% for eight subjects not producing methane (P = 0.02). The 11 methane producers showed a 93% increase in breath-methane excretion on resistant starch (P = 0.03). Continued consumption of 28 g type II resistant starch/d is well tolerated and increases colonic fermentation in healthy volunteers.