The Interplay Between GLP-1-Based Therapies, the Gut Microbiome, and MASLD/MASH in Type 2 Diabetes Mellitus: A Narrative Review

, and ameliorated MASLD in murine models. In clinical studies, tirzepatide achieved MASH resolution in 44-62% of patients in the phase 2 SYNERGY-NASH trial. In August 2025, the FDA approved semaglutide for MASH with fibrosis based on the Phase 3 ESSENCE trial. A recent longitudinal study in T2DM patients showed that baseline microbiome composition predicted glycemic response to semaglutide, without significant changes in microbiome diversity. In conclusion, GLP-1-based therapies demonstrate consistent preclinical associations with gut microbiome modulation and reduction in hepatic steatosis. Baseline microbiome composition has been suggested as a potential predictor of treatment response, supporting a personalized approach to MASLD management and warranting future clinical studies.