INFLUENCE OF LONG-TERM FEEDING OF DIFFERENT PURIFIED DIETARY-FIBERS ON CECAL MICROFLORA COMPOSITION AND ITS METABOLIZING ACTIVITY ON BILE-ACIDS

The aim of the study was to investigate the effect of four weeks inges tion of 10% fiber diets (cellulose, lignocellulose, pectin and guar gu m) and a fiber-free diet on cecal microflora composition and its prima ry bile acid metabolizing activity in vitro in female Sprague Dawley r ats. There was no difference in the qualitative and quantitative cecal microflora composition in rats fed cellulose and lignocellulose diets and those fed fiber-free diet. Guar gum and pectin diets significantl y increased Bacteroidaceae compared to cellulase and lignocellulose di ets. The counts of bifidobacteria were significantly higher in rats fe d guar gum than in all the other groups. Clostridia were present in hi gh counts in rats fed guar gum and pectin and generally absent in all the other groups. As regards 7 alpha-dehydroxylating cholic and chenod eoxycholic microorganisms, cellulose and lignocellulose diets signific antly decreased these microbial counts compared to all the diets. The results show that dietary fiber can induce alterations of cecal microf lora composition and intestinal bile acid metabolism.