Multi-omics reveals an association of the gut butyrate-IDO1-tryptophan axis with Yinchenhaotang plus Zexietang-ameliorated NASH in a microbiota-dependent manner

Our findings demonstrate that YCHZX alleviates NASH in a gut microbiota-dependent manner. We propose a mechanism whereby YCHZX enriches butyrate-producing bacteria, which is associated with the suppression of colonic IDO1 and a shift in tryptophan metabolism toward ILA production. The increased ILA, in turn, contributes to the activation of the AhR, thereby restoring gut barrier integrity and mitigating liver inflammation.