Butyric acid plays a crucial role in maintaining intestinal integrity by upregulating the expression of tight junction protein and mucin, which can improve intestinal barrier function and prevent toxic compounds (such as proinflammatory molecules) from migrating to the liver and inhibiting cholesterol synthesis, thereby decreasing liver fat accumulation and regulating the development of NAFLD (Pirola and Sookoian, 2021; Sun et al., 2021). The gene discussed is MUC5AC; the disease is metabolic dysfunction-associated steatotic liver disease.