Biotransformed product, genistein 7-O-phosphate, enhances the oral bioavailability of genistein

• Genistein 7-O-phosphate (G7P) is generated from a biotransformation process.
• G7P shows highly aqueous solubility and rapid dissolution.
• G7P enhances the intestinal permeability of genistein in vitro and in situ.
• G7P shows better oral bioavailability than genistein in rats.
• G7P may lead to better ingredient selection than genistein.

Research has indicated the health beneficial effects of soyfoods. Genistein, one of the primary bioactive agents in soybeans, has a number of pharmacological and biological activities; however, its low water solubility and low intestinal permeability may lead to the depletion of genistein absorption from dietary intake and contribute to its poor oral bioavailability. Previous study revealed a water-soluble phosphate conjugate of genistein, genistein 7-O-phosphate (G7P), generated by biotransformation of Bacillus subtilis var. natto BCRC80517 with genistein. This study aimed to investigate the dissolution profile, intestinal permeability and oral bioavailability of genistein and G7P. G7P improved water solubility and also enhanced intestinal permeability in vitro and in situ, and greatly increased plasma exposure to genistein after oral administration in rats. The aqueous solubility of genistein is the absorption barrier to its oral bioavailability. G7P may be a promising and efficient alternative to genistein.