Bile acid metabolism in rats fed two levels of corn oil and brans of oat, rye and barley and sugar beet fiber.
High concentrations of fecal bile acids are associated with a higher incidence of colon cancer. Dietary changes that alter bile acid metabolism are therefore of interest. Here, we report the effect of feeding diets containing four fiber sources and two fat levels for 7 wk on bile acid excretion and small intestinal bile acids (an index of pool size) in rats. The fiber sources were oat bran, rye bran, barley bran and sugar beet fiber. Fiber-containing diets were 8% dietary fiber and contained either 5 or 20% corn oil. All fiber sources caused significantly greater fecal output compared with the fiber-free basal diet. All fiber sources also resulted in significantly (P less than 0.05) lower fecal bile acid concentration compared with the fiber-free basal diet. Only rye bran resulted in significantly (P less than 0.05) higher total fecal bile acid excretion. Oat bran resulted in a slightly but significantly (P less than 0.05) higher quantity of small intestine bile acids compared with the other diets. Dietary fat level had no significant effect on fecal bile acid concentration or excretion or quantity of small intestinal bile acids. We conclude that all four fiber sources tested resulted in lower fecal bile acid concentration, by effectively causing greater fecal mass. Changes in dietary fat level as corn oil had no effect on fecal bile acids.
Gallaher
D D
DD
Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108.
Locket
P L
PL
Gallaher
C M
CM
D000818:Animals; D001647:Bile Acids and Salts / Q000032:analysis / Q000378:metabolism*; D001835:Body Weight; D003110:Colonic Neoplasms / Q000209:etiology / Q000517:prevention & control; D003314:Corn Oil / Q000008:administration & dosage*; D003672:Defecation; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage*; D004435:Eating; D002523:Edible Grain; D005243:Feces / Q000737:chemistry; D005766:Gastrointestinal Contents; D001467:Hordeum; D007421:Intestine, Small / Q000033:anatomy & histology / Q000737:chemistry; D008297:Male; D009929:Organ Size; D051381:Rats; D012434:Secale
D001647:Bile Acids and Salts; D004041:Dietary Fats; D004043:Dietary Fiber; D003314:Corn Oil