Biomaterial Database

Effect of dietary fiber on colonic bacterial enzymes and bile acids in relation to colon cancer. 1992

B S Reddy, and A Engle, and B Simi, and M Goldman

Division of Nutritional Carcinogenesis, Ameican Health Foundation, Valhalla, New York.

Because of the potential significance of colonic bacteria and secondary bile acids in the pathogenesis of colon cancer, the present study investigated the effect of different types of dietary fiber on fecal bacterial enzymes, namely, beta-glucuronidase, 7 alpha-dehydroxylase, nitroreductase, and azoreductase, and on bile acids and neutral sterols in premenopausal women. The subjects consumed 13-15 g of wheat, oat, or corn bran daily for 8 weeks in addition to their normal diet. Stools collected during the normal and fiber diet periods were analyzed for the above constituents. Dietary wheat bran decreased the concentrations of fecal deoxycholic acid, lithocholic acid, 12-ketolithocholic acid, and neutral sterols and the activities of all bacterial enzymes. Oat bran had no effect on secondary bile acids and 7 alpha-dehydroxylase but decreased beta-glucuronidase, nitroreductase, and azoreductase levels. Dietary corn bran increased 7 alpha-dehydroxylase, lithocholic acid, and cholesterol levels and decreased deoxycholic acid coprostanol, cholestenone, nitroreductase, and azoreductase levels. These results show that the modifying effect of dietary fiber on secondary bile acids and bacterial enzymes that may play a role in carcinogenesis depends on the type of fiber consumed.

UI	MeSH Term	Description	Entries
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental
D003110	Colonic Neoplasms	Tumors or cancer of the COLON.	Cancer of Colon,Colon Adenocarcinoma,Colon Cancer,Cancer of the Colon,Colon Neoplasms,Colonic Cancer,Neoplasms, Colonic,Adenocarcinoma, Colon,Adenocarcinomas, Colon,Cancer, Colon,Cancer, Colonic,Cancers, Colon,Cancers, Colonic,Colon Adenocarcinomas,Colon Cancers,Colon Neoplasm,Colonic Cancers,Colonic Neoplasm,Neoplasm, Colon,Neoplasm, Colonic,Neoplasms, Colon
D004043	Dietary Fiber	The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.	Fiber, Dietary,Roughage,Wheat Bran,Bran, Wheat,Brans, Wheat,Dietary Fibers,Fibers, Dietary,Roughages,Wheat Brans
D005243	Feces	Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D001419	Bacteria	One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.	Eubacteria
D001647	Bile Acids and Salts	Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.	Bile Acid,Bile Salt,Bile Salts,Bile Acids,Acid, Bile,Acids, Bile,Salt, Bile,Salts, Bile