Banxia Xiexin Decoction (BXD) is a traditional herbal formulation with a bitter flavor that has a long-standing history of use in Asia for treating functional dyspepsia (FD). In traditional Chinese medicine, the bitter flavor is believed to play a critical role in the therapeutic activity of BXD. The ethnopharmacological properties of bitter plant extracts are closely associated with their anti-inflammatory effects, which may contribute to their efficacy in FD. However, the specific mechanisms remain unknown. The objective of this study is to uncover the bitter active compounds of BXD and their effects in the treatment of FD. The chemical compounds of BXD were identified using HPLC-Q-Exactive-MS. Active compounds in BXD were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, and bitter active compounds were further identified using BitterDB and PlantMolecularTasteDB. Molecular docking was employed to identify potential targets of these bitter active compounds, and their activation was validated through flow cytometry analysis of Ca²⁺. Subsequently, a mouse model of FD was established, and our hypothesis was further validated using enzyme linked immunosorbent assay, immunohistochemistry, immunofluorescence, and western blotting. Through HPLC-Q-Exactive-MS analysis, TCMSP, BitterDB, and PlantMolecularTasteDB database, a total of 11 bitter active compounds in BXD were identified: Baicalein, Baicalin, Berberine, Coptisine, Formononetin, Isorhamnetin, Kaempferol, Naringenin, Palmatine, Quercetin, and Wogonin. Molecular docking results indicated that these active compounds exhibited strong affinity for TAS2R38, with Berberine showing the highest scoring. Flow cytometry analysis of Ca²⁺ revealed that both Berberine and BXD elevated intracellular calcium concentrations, although this effect was partially antagonized by the TAS2R38 inhibitor probenecid. In vivo experiments demonstrated that BXD effectively improved eosinophil infiltration in the duodenum of FD mice, downregulated the expression of inflammatory factors IL-1β, IL-5, and TNF-α, inhibition of NF-κB signaling pathway activation, alleviated damage to the duodenal mucosal barrier, and reversed gastrointestinal motility disorders, with the therapeutic effect enhancing with increasing doses of BXD. However, this therapeutic effect was partially inhibited following probenecid intervention. BXD contains numerous bitter active compounds that play a significant role in regulating inflammatory activity in the duodenum of FD through the activation of TAS2R38. This finding unveils, for the first time, the ethnopharmacological activity of bitter plant taste agents in anti-inflammatory effects, providing new insights for the treatment and drug development of FD.

Banxia Xiexin Decoction (BXD) is a traditional herbal formula with a history spanning over a millennium, significantly contributing to the treatment of gastrointestinal disorders, especially gastric precancerous lesions (GPL) such as gastritis, intestinal metaplasia, and dysplasia. Although it is effective in reducing inflammation, enhancing intestinal metaplasia, and providing antitumor benefits, the exact mechanisms of its action are not yet understood. This study aims to clarify how BXD influences the gastric microbiota to enhance GPL. A GPL model was developed using N-Methyl-N'-nitro-N-nitrosoguanidine. The pharmacological effects of BXD on GPL were evaluated using ELISA, qPCR, AB-PAS staining, immunohistochemistry, H&E staining, Western blotting, and immunofluorescence. Subsequently, the protective effects of BXD against MNNG-induced GES-1 cells were evaluated in vitro. Furthermore, network pharmacology was employed to analyze the underlying mechanisms of BXD in the treatment of GPL. 16S rRNA sequencing was further employed to examine the structure and stability of the gastric microbiota. Finally, the roles of Lactobacillus and Streptococcus in GPL were further validated through animal experiments. The BXD intervention decreased TNF-α, IL-1β, and IL-6 levels in both gastric tissue and serum of GPL mice, enhanced IL-10 production, ameliorated intestinal metaplasia, and suppressed Ki67 and p53 expression. BXD mitigated gastric mucosal injury by upregulating the expression of Zonula occludens-1, E-cadherin, and Occludin, as well as inhibiting the PI3K-Akt and MAPK signaling pathways. Furthermore, BXD improved the dysbiosis of the gastric microbiota in GPL mice.The gastric microbiota of mice at the phylum level predominantly consisted of Bacillota, Proteobacteria, Cyanobacteria, Bacteroidota, Actinobacteria, Desulfobacterota, and Campylobacterota.In GPL mice, dysbiosis was notably marked by an increased presence of Bacillota and Proteobacteria, with Lactobacillus and Streptococcus at the genus level being significant contributors to GPL progression. The BXD intervention restored gastric microbiota balance by enhancing Bacillota and Lactobacillus abundance while reducing Proteobacteria and Streptococcus richness. Further intervention with Lactobacillus improved gastric mucosal atrophy and intestinal metaplasia associated with GPL, leading to a reduction in the levels of TNF-α, IL-1β, and IL-6 in gastric tissues, while enhancing the production of IL-10. This treatment also promoted the expression of Zonula occludens-1, E-cadherin, and Occludin, and inhibited the activation of the PI3K-Akt and MAPK signaling pathways. In contrast, treatment with Streptococcus in GPL mice resulted in more severe gastric mucosal atrophy and intestinal metaplasia, marked by increased levels of TNF-α, IL-1β, and IL-6, reduced IL-10 production, no significant increase in the expression of Zonula occludens-1, E-cadherin, and Occludin, and enhanced activation of the PI3K-Akt and MAPK signaling pathways. BXD intervention demonstrated significant therapeutic effects in GPL mice. The underlying mechanisms are associated with the restoration of gastric microbiota dysbiosis, promotion of beneficial bacterial growth, suppression of potential pathogens, modulation of the inflammatory response, and alleviation of mucosal damage.