GCG and type 2 diabetes mellitus: Data from preclinical and clinical trials have shown that BAs, by activating the Takeda G-protein receptor 5 (TGR5) on enteroendocrine L cells, increase both the glucagon-like peptide-1(GLP-1) and insulin secretion, and postprandial glycemia, which might have a beneficial effect in T2DM [13–16].