[Effect of diet and of the microbial flora of the digestive tract on the intestinal pool and fecal excretion of bile acids in the rat: a comparative study in axenic, ghotoxenic and holoxenic rats].

When axenic rats are given a microflora which causes the caecum distension present to disappear but does not metabolize bile acids, the intestinal pools and fecal excretion of bile acids are intermediary between those of axenic and those of holoxenic rats. This flora acts non-specifically on bile acids metabolism by changing the physiological characters related to caecal distension in axenic rats. The intestinal pools and fecal excretion of bile acids are higher in rats given a commercial chow than in those receiving a semi-synthetic feed containing the same amount of cholesterol; the difference between axenic and holoxenic rat fecal excretions is greater than in rats given the semi-synthetic feed. This wider difference is especially due to greater fecal excretion of bile acids in holoxenic rats given the commercial diet; it is thus related to modification of the gut microbial flora due to diet.