[Dietary factors to induce and suppress colon cancer development]

It has been clear that the promoting stimulus from bile acids and other colonic constituents play an important role in colon cancer induction in man and in animal models, although essential for the initiation of this cancer probably is relatively week. The level and concentration of bile acids in the colon largely depend on the amount of dietary fat and fiber. High fat diet increases fecal bile acids, and fiber increases the fecal volume and may have a protecting effect through dilution of the bile acids in presenting to the colonic mucosa. It is suggested in animal models that changes of the enterohepatic circulation of bile acids following surgery such as cholecystectomy and right-sided hemicolectomy could provide another cocarcinogenic stimulus or anticarcinogenic mechanism in the development of this cancer.