Interestingly, we did not find a positive effect of FMT on NAFLD, although there are a few studies indicating that FMT could alleviate high-fat-induced steatohepatitis and improve insulin sensitivity, which were correlated with an increase in the tight junction of small intestinal and butyrate-producing bacteria (12, 13). This evidence concerns the gene INS and metabolic dysfunction-associated steatotic liver disease.