EFFECTS OF FISH-OIL ON FECAL BACTERIAL ENZYMES AND STEROID-EXCRETION IN HEALTHY-VOLUNTEERS - IMPLICATIONS FOR COLON-CANCER PREVENTION

Diet-induced changes in fecal excretion of secondary bile acids, certa in neutral sterols, and bacterial enzyme activities are known to play a role in colon cancer development. Dietary fish oil (FO) has been imp licated as a protective agent in colon carcinogenesis. In the present study, the effects of FO and corn oil (GO) on these fecal parameters w ere investigated in 24 healthy volunteers consuming a low- or a high-f at diet (30% or 50% of energy derived from fat). After four weeks of F O or CO supplementation (4.4 g of n-3 fatty acids/day), no significant differences were noted for fecal activities of beta-glucuronidase, be ta-glucosidase, and sulfatase, nor was fecal bile acid excretion signi ficantly affected by FO or CO consumption. However, daily excretion of the putative colon carcinogen 4-cholesten-3-one was significantly low er in the FO than in the CO period during low- and high-fat experiment s. This may be another biochemical mechanism by which FO exerts its pr otective effect on colon cancer development.