Blue Whiting (Micromesistius poutassou) Protein Hydrolysates Elicit Hydrolytic Enzyme-Dependent Improvements in Acute Postprandial Blood Glucose and Pancreatic Islet Health in a High-Fat Fed Diet-Induced Obese Mouse Model

Improvement of dietary protein content is of high interest for increasing the success of dietary intervention for management of metabolic diseases such as obesity/type-2 diabetes. The prevalence of metabolic diseases is increasing globally, and most patients progress to long-term pharmaceutical management. Blue whiting is an underutilized fish species with a high protein quality, representing a sustainable opportunity to improve upon current dietary intervention strategies. This study investigated the antidiabetic and appetite-suppressant potential of blue whiting protein hydrolysates (BWPHs) in an acute in vivo setting and in a chronic, diet-induced obese model. In acute studies in healthy mice, one BWPH (BW-SPH-A) elicited a 24.1% reduction in food intake (p < 0.05) and another BWPH (BW-SPH-C) induced a significant improvement in blood glucose excursion (p < 0.05). The effect of these two BWPH in a disease model was then assessed using C57Bl/6J mice fed a high-fat (45% kcal), high-sucrose (30% kcal) diet for 12 weeks. In this setting, neither BWPH appeared to significantly influence bodyweight or blood glucose. However, BW-SPH-C appeared to induce significant increases in average pancreatic islet area (p < 0.001) and proliferation of beta-cells (p < 0.01), along with a significant decrease in α-cell proliferation (p < 0.001), which highlights the potential of this BWPH for the long-term management of T2DM. Further investigation of this BWPH in more severe models of T2DM is warranted.