Effects of Cereal-Derived Proteins and Peptides on Blood Glucose Levels

Some cereal proteins and their digestive peptides exhibit the potential to regulate blood glucose levels, which is important for the management of diabetes and its complications. Proteins in common grains, such as wheat and buckwheat, and in legumes, such as kidney beans and soybeans, contain proteinaceous α-amylase inhibitors (α-AIs) that inhibit the breakdown of starch into reducing sugars, thereby mitigating postprandial glucose spikes. Indigestible cereal proteins function similarly to dietary fibers by adsorbing glucose and facilitating its excretion and stabilizing blood glucose levels. Moreover, peptides derived from these proteins can suppress glucose transporter expression in the intestine, thereby reducing glucose absorption. They also promote insulin secretion by inhibiting dipeptidyl peptidase-IV (DPP-IV), an enzyme that breaks down incretin hormones. Collectively, these properties highlight the potential of cereal proteins and peptides in functional foods for blood glucose management.