The hormone FGF15/19, which is secreted from the small intestine (ileum), is a hormone that improves glucose and lipid metabolism. Obesity and type 2 diabetes tend to decrease blood FGF15/19 concentrations, and gastric bypass surgery is the only way to improve them.
Prof. Nonogaki and his colleagues have found that feeding mice whey protein in addition to their normal diet decreased the expression of the transporter OSTα/β, which excretes bile acids in the intestinal cells of the small intestine (ileal part), increased the expression and secretion of FGF15, and suppressed liver glycogenesis and synthesis and secretion of bile acids.
Furthermore, we found that GLP-1 and serotonin synthesis was suppressed in the small intestine, and blood serotonin and insulin levels were decreased.
On the other hand, administration of the soy-derived protein β-conglycinin had the opposite effect of these effects of whey protein.
Thus, it was confirmed that the intestinal-liver-pancreatic network, which controls metabolism in vivo, operates differently depending on the type of protein ingested in the diet.
Combined with the previous findings of this research group (click here for previous presentation), it is expected that appropriate dietary protein intake will lead to new treatments for obesity, type 2 diabetes, fatty liver, and other diseases that do not depend on gastric bypass.
The results were published in Frontiers in Endocrinology on January 27, 2023.