Fibroblast growth factor 19 (FGF19) is an ileum-derived postprandial enterokine that governs bile acid and nutrient metabolism. Synthesis of FGF19 is up-regulated by bile acids and, conversely, bile acid synthesis is down-regulated by FGF19. FGF19 also controls gallbladder volume. FGF19 has been shown to have profound effects on glucose and lipid metabolism. Recent studies have described FGF19 as a postprandial regulator of hepatic glucose and protein metabolism. Like insulin, FGF19 induces protein and glycogen synthesis and suppresses gluconeogenesis in liver. However, unlike insulin, FGF19 does not stimulate lipogenesis. A key difference between FGF19 and insulin lies in their use of different cellular signaling pathways. The beneficial effects of FGF19 on liver metabolism raise the question of whether FGF19 and its variants can be used as therapeutic agents in the treatment of diabetes.
