Huangqin Tea Total Flavonoids-Gut Microbiota Interactions: Based on Metabolome and Microbiome Analysis

Huangqin tea (HQT), a Non-Camellia Tea derived from the aerial parts of Scutellaria baicalensis, is widely used in the north of China. The intervention effects of HQT on intestinal inflammation and tumors have been found recently, but the active ingredient and mechanism of action remain unclear. This study aimed to investigate the interactions between the potential flavonoid active components and gut microbiota through culture experiments in vitro combined with HPLC-UV, UPLC-QTOF-MS, and 16S rDNA sequencing technology. The results showed that the HQT total flavonoids were mainly composed of isocarthamidin-7-O-β-D-glucuronide, carthamidin-7-O-β-D-glucuronide, scutellarin, and others, which interact closely with gut microbiota. After 48 h, the primary flavonoid glycosides transformed into corresponding aglycones with varying degrees of deglycosylation. The composition of the intestinal microbiota was changed significantly. The beneficial bacteria, such as Enterococcus and Parabacteroides, were promoted, while the harmful bacteria, such as Shigella, were inhibited. The functional prediction results have indicated notable regulatory effects exerted by total flavonoids and scutellarin on various pathways, including purine metabolism and aminoacyl-tRNA biosynthesis, among others, to play a role in the intervention of inflammation and tumor-related diseases. These findings provided valuable insights for further in-depth research and investigation of the active ingredients, metabolic processes, and mechanisms of HQT.