Bifidobacterium breve MCC1274 with glycosidic activity enhances in vivo isoflavone bioavailability

Abstract

Polyphenols are plant derived compounds that exert many beneficial health effects to the human host. However, associated health benefits of dietary polyphenol are highly dependent on their intestinal metabolism, bioavailability, and absorption. Bifidobacteria, which represent the key members of gut microbiota, have been suggested to promote gut microbial homeostasis and may be involved in the metabolism of polyphenols. In this study, the capabilities of thirteen <i>Bifidobacterium</i> strains in hydrolysing polyphenol glycosides were evaluated. Among the tested strains, <i>Bifidobacterium breve</i> MCC1274 was found to possess the highest β-glucosidase activity and strong capability to convert daidzin and trans-polydatin to their aglycones; while kinetic analysis revealed that <i>B. breve</i> MCC1274 hydrolysed more than 50% of daidzin and trans-polydatin at less than 3 h of incubation. Further investigation using rats with an antibiotics-disturbed microbiome revealed that following the ingestion of daidzin glycoside, oral administration of <i>B. breve</i> MCC1274 significantly enhanced the plasma concentration of daidzein in rats pre-treated with antibiotics as compared to antibiotics-pre-treated control and non-treated control groups. The relative abundance of <i>Actinobacteria</i> and the total numbers of <i>B. breve</i> were also significantly higher in antibiotics-pre-treated rats administered with <i>B. breve</i> MCC1274 than that of the control groups. These findings suggest that <i>B. breve</i> MCC1274 is effective in enhancing the bioavailability of daidzein in the gut under dysbiosis conditions and may potentially improve intestinal absorption of isoflavones and promote human health.