Regulation of gut microbiota of Astragali Radix in treating for chronic atrophic gastritis rats based on metabolomics coupled with 16S rRNA gene sequencing

Astragali Radix (HQ), a common traditional Chinese medicine (TCM), is widely used to treat chronic atrophic gastritis (CAG). However, its mechanism in treating CAG is still not clear. Accumulating evidence highlights the link between gut microbiota and CAG. We hypothesized that the gut microbiota might be involved in the effect of HQ. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-Q-TOF/MS) based metabolomics and 16S rRNA gene sequencing techniques of the cecal contents were applied to study its mechanisms. As a result, nine metabolites and fifteen gut microbiotas changed significantly in cecal contents samples between control group and model group. Among them, two metabolites (7-keto-3A ·12-α-hydroxyalkanoic acid and deoxycholic acid) and two gut microbiota genera (Acetobacter and Escherichia), had the most obvious callback effect after the administration of HQ. Sixty-seven correlated pairs exhibited the significant link between the involved metabolites and gut microbiotas through the correlation analysis, where two strong correlation pairs: Tetrahydrohydroxone ∼ Bacteroides (r = 0.895) and Deoxycholic acid ∼ Acetobacter (r = -0.843) were regulated by HQ. The results showed that HQ had the potential protection from metabolic perturbation involved into gut microbiotas induced by CAG. Two gut microbiotas, Acetobacter and Escherichia, and two metabolites, 7-keto-3A ·12-α-hydroxyalkanoic acid and deoxycholic acid were the potential targets of HQ.