INS and type 2 diabetes mellitus: In NAFLD, increased fiber intake was associated with reduced liver fat and aminotransferases, partly via increased SCFAs and improved insulin sensitivity. SCFAs (especially butyrate) from fiber have anti-inflammatory and insulin-sensitizing effects, aiding glycemic control. Some patients saw improved HOMA-IR and slight HbA1c reductions with fermentable fiber supplementation. Overall, dietary fiber supported weight management and metabolic health, which benefited both T2D and NAFLD.