Microbial conversion of daidzein affects fecal equol concentration and bacterial composition of rats with or without ovariectomy

Abstract:

Abstract:Equol is the end metabolite of daidzein by certain intestinal bacteria，which has stronger bioactivity comparing with daidzein．［Objective］To evaluate the role of orally administrated equol-producing bacterium on increasing equol production and shifting intestinal microbiota of embracer animal．［Methods］In total 60 rats with or without ovariectomy at average bodyweight 211 ± 9g were divided into 5 groups． The differences on equol concentration and bacterial composition were compared in rats orally treated with distilled water，estradiol，daidzein，equol and daidzein + ZX7． ［Results］ The fecal equol concentration in daidzein groups was significantly higher than that in control and estradiol groups． The fecal equol concentration in daidzein + ZX7 groups was comparable to that in equol groups． Principal Components Analysis (PCA) of fecal DGGE profiles showed clear difference of fecal microbiota between ovariectomy done or undone rats． Fecal population of Bacteriodetes showed strong correlation with fecal equol concentration． ［Conclusion］Normal intestinal microbiota in rats might have the capacity to convert daidzein into equol． Dietary source of equolproducing bacterium ZX7 might have the possibility to increase the equol production of embracer animal． Endogenous estrogen concentration might shift the intestinal microbiota on rats． Bacteriodetes might have an important role on equol production．