Impact of Dietary Polydextrose on the Daidzein Metabolism in Adult Mice

Equol, a bacterial product from daidzein, has been shown to provide beneficial effects. The impact of polydextrose, a compound known to affect the intestinal flora, was studied for its impact on mouse intestinal flora and isoflavonoids in the cecum and plasma. We hypothesized that polydextrose would change the metabolism of isoflavonoids and intestinal flora in mice. Male mice were administered a 1% polydextrose solution (PD) in their drinking water which was provided ad libitum, and were compared with a control group (CO, water only). Both groups were fed the AIN-93M diet for 24 days. Plasma equol and cecal equol concentrations and in vitro equol production from daidzein with fecal flora of mice were measured. The plasma equol concentration was significantly higher in the PD group than in the CO group at 22 hr after the administration of daidzin. The concentration of equol in the cecum was signiticantly greater in the PD group than in the CO group at 22 hr after administration of daidzin. In the in vitro incubation of daidzein with the fecal flora of mice, equol concentrations were greater in the PD group. These results suggest that dietary polydextrose has the potential to affect equol production by altering the metabolic activity of the intestinal flora and/or the gut environment.