The metabolites of flavonoids with typical structure enhanced bioactivity through gut microbiota

The degradation of flavonoids helps to elucidate the mechanism of their biological activity, thus guiding individuals to better ingestion and utilization of these compounds. In this study, seven kinds of flavonoids with typical structures were in vitro fermented by fresh feces, and the degradation process of flavonoids were monitored by HPLC, and the gut microbiota constitutes were analyzed by 16S rRNA microbiota sequencing. Results indicated that all seven kinds of flavonoids could be degraded by intestinal microbiota. In addition, the degradation products of flavonoids showed excellent antioxidant and anti-inflammatory activity, especially the degradation products of epicatechin at 24 h exhibited the strongest scavenging capacity for FRAP and ABTS free radicals, which were 287.494±16.941 μM and 567.344±13.477 μM, respectively. Moreover, compared with the corresponding control group, flavonoid treatment changed the composition of the gut microbiota, mainly by significantly reducing the abundance of harmful bacteria, such as Proteobacteria, and increasing the abundance of beneficial bacteria, such as Flavonifractor. This paper might provide theoretical basis and technical support for the nutritional and pharmacological applications of flavonoids.