Abstract: These guidelines present standardized recommendations for the microecological therapy of metabolic dysfunction-associated fatty liver disease (MAFLD). The core role of gut-liver axis dysfunction in the pathogenesis of MAFLD is systematically elaborated, and the diagnostic methods for intestinal microecological imbalance are clearly def ined herein. The application of various microecological preparations, including probiotics, prebiotics, synbiotics and postbiotics, is emphatically recommended, and the donor screening, product preparation, indications, operation procedures, follow-up monitoring and ef f icacy evaluation criteria for fecal microbiota transplantation are standardized in detail. The authors formulated these guidelines to provide evidence-based decision-making references for clinicians applying microecological therapy for MAFLD, with the aim of optimizing patient management and ensuring the safety and ef f icacy of treatment.