Traditional Chinese Medicine Modulation of the Gut–Liver Axis: From Barrier Disruption to Inflammasome Activation in MASLD/MASH

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its inflammatory-fibrotic phenotype (MASH) exhibit pronounced immunometabolic coupling. This review synthesizes evidence along the gut-liver axis, from epithelial tight-junction and gut vascular barrier (GVB) failure to TLR4-MyD88/TRIF-NF-κB amplification and NLRP3 inflammasome activation and outlines the logic of the gut-derived exposure spectrum-lipopolysaccharide (LPS), endogenous ethanol, bile acids (BAs), short-chain fatty acids (SCFAs), and trimethylamine N-oxide (TMAO). We position BA-FXR/TGR5, SCFAs-GPR41/43, and AMPK/Nrf2 as upstream/downstream modulators that reset inflammatory thresholds and confer stage-dependent druggability. Based on node-to-pathway mapping, we summarize mechanisms and translational signals for berberine (BBR), Qushihuayu (QSHY), Da-Chai-Hu Decoction (DCHD), and polysaccharides (e.g., Astragalus, Ganoderma), emphasizing pharmacokinetic and site-of-exposure constraints that support "gut-first" actions. We propose a minimal companion biomarker set-LBP/sCD14, BA profiles with FGF19-C4 dynamics, and IL-1β/GSDMD-N-paired with hierarchical imaging gates (≥30% relative MRI-PDFF decline; MRE/ELF) to underpin response typing and go/no-go decisions. Finally, we highlight critical gaps (direct human GVB readouts; longitudinal multi-omics bridged to clinical outcomes) and outline a biomarker-driven multi-arm multi-stage (MAMS) pathway for adaptive, stratified development of multi-target traditional medicine interventions in MASLD/MASH.