Effects of corn fiber residue (5g/day for 10 days) on fecal weight, moisture, pH, fecal flora, ammonia content, and on the activities of β-glucuronidase and β-glucosidase were investigated in six healthy subjects. Corn fiber residue was remnant of hemicellulose extraction from corn fiber by calcium hydroxide. Fecal weight showed a tendency to increase, and fecal pH did not change during corn fiber residue supplementation. No remarkable changes in the fecal flora at the bacterial group level were observed. Fecal ammonia content and β-glucuronidase activity per gram of wet feces decreased slightly but the daily output did not change. Fecal β-glucosidase activities per gram of wet feces increased significantly (p<0.05) and the daily output also tended to increase during corn fiber residue supplementation.