GCG and type 2 diabetes mellitus: Finally, in a new randomized controlled trial, Zhao and his colleagues showed that in patients with T2DM a high-fiber diet promotes SCFA-producing gut bacteria, which in turn normalizes levels of HbA1c via an increase in the production of glucagon-like peptide 1 (GLP1) [30].Overall, the importance of increasing intake of dietary fiber must be emphasized in the T2DM population (particularly in newly-diagnosed T2DM).