The Concentration of Bile Acids in the Fecal Stream as a Risk Factor for Colon Cancer
It is usual when considering the origin of human cancers to focus on the initiating carcinogenic factors. For colon cancer we think in terms of fecal and food mutagens—the fecapentaenes (8), the aromatic amines (2), the aromatic hydrocarbons (18), lipid oxidation products such as malonaldehyde (10), and cholesterol oxidation products (17). But of perhaps equal or greater importance are co-carcinogenic and promoting factors that increase the vulnerability of normal cells to the carcinogens in their environment. With colon cancer we think here of the dietary fat and fecal bile acids. The secondary bile acids are known to reduce the integrity of the mucosal barrier (5), to increase the sensitivity of cells to mutagenic (15) and carcinogenic agents (16), to increase the proliferation rate of crypt cells (7), and to act as promoters of experimental colon carcinogenesis (6). Yet despite these factors, an unambiguous role of bile acids in human colon carcinogenesis has not been established.
KeywordsBile Acid Cholic Acid Deoxycholic Acid Colonic Epithelium Beef Tallow
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