FMT effectively decreased CD3+CD4+ T cells, CD3+CD8+ T cells and M1 macrophages in liver and Th1 cells in MLN, whereas it increased Treg cells, thereby decreasing plasma ALT, AST, TG and TCHO, as well as histologically attenuating hepatic steatosis and lipid accumulations, thus improving NAFLD. The gene discussed is CD4; the disease is metabolic dysfunction-associated steatotic liver disease.