The effects of Bifidobacterium longum HY8001 supplement intake on the fecal microflora and fecal bacterial enzyme activity were studied in ten healthy human volunteers, before, during and after intake (respectively for 3 weeks). During intake of B. longum HY8001 supplement, fecal, $eta$-glucuronidase and nitroreductase activities significantly decreased 44.6%(p<0.005) and 32.3%(p<0.01), respectively. Although numbers of major bacterial groups of fecal microflora were not affected by B. longum HY8001 intake for 3 weeks, the number of Bifidobacterium was significantly increased (p<0.05). This result indicates that intake of B. longum HY8001 might be potentially beneficial for the prevention and inhibition of colon cancer and improvement of human intestinal microflora composition.