Effects of a mixture of organisms,Lactobacillus acidophilusorStreptococcus faecalison cholesterol metabolism in rats fed on a fat- and cholesterol-enriched diet

Abstract

The effect of a mixture of organisms (a probiotic mixture) comprisingBacillus, Lactobacillus, Streptococcus, Clostridium, SaccharomycesandCandida(107–8colony-forming units/g rice bran of each component) on lipid metabolism was compared with that ofL. acidophilusand that ofS. faecalis. There were four treatment groups: rice bran (control), the mixture of organisms,L. acihphifusorS. faecds(30g/kg) were given to rats in a fat- and cholesterol-enriched diet for 4 weeks. The serum total cholesterol concentration of the group fed on the mixture of organisms was reduced by 15–33% compared with the other groups at the end of the 4week feeding period (P< 0·05). This group also had a lower hepatic cholesterol concentration (36–44%) than the two single-bacteria groups (P< 0·05). 3-Hydmxy-3-methylglutaryl-Co A reductase (NADPH; EC 1.1.1.34) activities of the mixed-organism andL. acidophifusgroups were significantly lower (61–63%) than those of the other groups (P< 0·05); the activity of the S. faecalis group was also signikantly lower (42%) than that of the control group (P< 0·05). The faecal cholesterol and bile acid concentrations of the mixed-organism group increased compared with those of theL. acidophilusandS. faecalisgroups (P< 0·05). The capacity of the mixed- organism cells to bind bile saltin vitrowas significantly higher (approximately 50%) than that of the singlebacteria cells (P< 0·05). On the other hand, cholesterol micelle formation for the mixed-organism cells was significantly (approximately 9%) lower than that of the singlebacteria cells (P< 0·05). These results indicate that the mixture of organisms decreased the synthesis of cholesterol in the liver and increased the loss of steroids from the intestine, in rats. Thus, the mixture of organisms had a hypocholeaterolaemic role