Anwei decoction alleviates chronic atrophic gastritis by modulating the gut microbiota-metabolite axis and <i>NLRP3</i> inflammasome activity

BACKGROUND Chronic atrophic gastritis (CAG) is a clinically refractory gastric disease often characterized by high recurrence rates and adverse drug reactions. Anwei decoction (AWD), a traditional Chinese medicine formula, has been shown to significantly improve clinical symptoms in patients with CAG, as demonstrated by a multicenter cohort study (overall effective rate: 82.5%, P < 0.01). However, the unclear molecular mechanisms and therapeutic targets of AWD limit its international acceptance. AIM To investigate the therapeutic mechanisms of AWD against CAG from an integrated perspective. METHODS In this study, N-methyl-N’-nitro-N-nitrosoguanidine was used to establish a CAG rat model. Serum-derived constituents transferred from AWD were first identified using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. The concentrations of inflammatory cytokines in serum samples were determined by enzyme-linked immunosorbent assay. Moreover, gastric mucosal tissues were analyzed by quantitative real-time polymerase chain reaction to measure messenger RNA (mRNA) levels of the NLRP3 inflammasome. Western blotting was used to detect the protein expression of NLRP3 , caspase-1, and interleukin (IL)-1β. To elucidate the regulatory mechanisms underlying AWD treatment, structural alterations of the gut microbiota (GM) and associated metabolites were analyzed using integrated high-throughput sequencing (16S rRNA) and liquid chromatography-mass spectrometry based untargeted metabolomics. This comprehensive approach systematically clarified AWD’s multi-target therapeutic mechanisms against CAG. RESULTS AWD notably reduced serum levels of pro-inflammatory cytokines, such as IL-1β, IL-18, tumor necrosis factor-α, and lipopolysaccharide, demonstrating significant statistical differences (all P < 0.01). Additionally, AWD substantially inhibited NLRP3 mRNA expression in gastric mucosal tissue (P < 0.01) and concurrently decreased the protein abundance of NLRP3 , IL-1β, and caspase-1 (all P < 0.01), thereby suppressing inflammasome signaling activation. GM analysis indicated that AWD intervention significantly increased the relative abundance of beneficial bacteria. Associated microbial metabolites likely inhibited the NLRP3 inflammasome pathway by modulating immune cell function. Non-targeted metabolomics further indicated that AWD exerted anti-inflammatory effects by regulating critical metabolic pathways, including the Kaposi’s sarcoma-associated herpesvirus infection pathway, autophagy processes, and glycosylphosphatidylinositol-anchor biosynthesis. CONCLUSION AWD alleviates the pathological progression of CAG through multi-target synergistic mechanisms. On one hand, AWD directly suppresses gastric mucosal inflammation by inhibiting NLRP3 inflammasome activation. On the other hand, AWD remodels intestinal microbiota-metabolite homeostasis, enhances intestinal barrier function, and regulates mucosal immune responses.