Additionally, SCFAs produced from the microbiota serve as an energy source for enterocytes and major signaling molecules in peripheral tissues by stimulating G-protein-coupled receptors (GPR 41, 43, 109), leading to improvements to metabolic disorders by enhancing the activities of intracellular mediators, such as AMPK and SIRT1 [37]. This evidence concerns the gene SIRT1 and metabolic disease.