The GLP-1/GLP-1R/cAMP/PKA/CREB/INS pathway enhances the management of T2DM under the influence of SCFAs [127]; SCFAs inhibit the HDAC3-H3K27ac-PPAR-γ axis, thereby reducing lipid storage in the body [128]. The gene discussed is INS; the disease is type 2 diabetes mellitus.