Effects of Rice Starch-Isoflavone Diet or Potato Starch-Isoflavone Diet on Plasma Isoflavone, Plasma Lipids, Cecal Enzyme Activity, and Composition of Fecal Microflora in Adult Mice

Abstract

The effects of rice starch-isoflavone diet or potato starch-isoflavone diet onplasma concentration of isoflavones, plasma lipids, cecal enzyme activity, and intestinalmicroflora were studied. Male 15-wk-old mice were fed a rice-starch-based or potatostarch-based diet supplemented with isoflavones for 4 wk, and plasma samples, cecal contents, and feces were collected individually. Plasma equol concentration was significantlyhigher in the potato-isoflavone diet group than in the rice-isoflavone diet group, but no significant difference was observed in plasma daidzein or genistein concentrations. Plasmatotal cholesterol concentration was higher in the potato-isoflavone diet group, but no significant difference was observed in plasma triglyceride concentration, Both cecal β-glucuronidase and β-glucosidase activities were significantly higher in the rice-isoflavone diet group. The number of bifidobacteria was significantly higher in the potato-isoflavone dietgroup. These results indicate that different types of starches have different influences on plasma isoflavone and suggest that the influences might be through the change of host physiology and/or the metabolism and composition of intestinal microflora.