Wheat fiber is a laxative and wheat protein may affect blood lipids. We therefore tested the effects on laxation and serum lipid metabolism of a novel source of wheat fiber and protein produced by the amylolytic digestion of starch from wheat. Twenty-four healthy men and women consumed 3 different test cereals in random order, each for 2 wk. The test supplement and the positive control, American Association of Cereal Chemists wheat bran supplement, both provided the same amount of fiber (21 g/d) and the negative control supplement provided 1.7 g fiber/d. The test supplement and the positive control supplement increased fecal bulk similarly (239.5+/-19 and 216.7+/-19 g/d, respectively) and significantly more than did the negative control supplement (165.6+/-16 g/d, P < 0.010). Compared with the negative and positive control supplements, the week 2 value of the test supplement for the ratio of total to HDL cholesterol was significantly reduced (P = 0.046). We conclude that the product of amylolytic digestion of starch from wheat flakes, which is high in wheat fiber and protein, has a fecal bulking effect similar to that of wheat bran and may have a beneficial effect on serum lipids.