A Hypoglycemic Peptide from Nut Oil Meal Improves Glycolipid Metabolism via Multi-Dimensional Regulation in Type 2 Diabetic Mice.

BACKGROUND AND METHODS

To address the need for dietary interventions in sub-healthy populations and promote sustainable utilization of agricultural by-products, we isolated hypoglycemic peptide (PHP) from nut oil meal through enzymatic extraction, ion exchange and gel chromatography purification, and simulated gastric digestion.

RESULTS

PHP exhibited significant inhibitory activity against α-amylase and α-glucosidase. In type 2 diabetic mice, PHP significantly ameliorated the "three-more-one-less" syndrome, reduced glycosylated hemoglobin and insulin levels, mitigated liver and kidney tissue lesions, and improved glucose and lipid metabolic disorders-effects partly supported by its enhancement of intestinal barrier function via restoring gut microbiota diversity. Gut microbiota analysis revealed that PHP exerts hypoglycemic effects by regulating gut microbial composition: increasing SCFA-producing taxa, reducing pro-inflammatory/metabolic disorder-associated taxa, and normalizing the Firmicutes/Bacteroidetes ratio. KEGG pathway analysis demonstrated that PHP mediates synergistic hypoglycemic effects by regulating carbohydrate metabolism, amino acid metabolism, and cofactor/vitamin metabolism.

CONCLUSIONS

This work provides a theoretical foundation for developing natural functional foods from agricultural by-products, supporting PHP's potential as a dietary supplement for metabolic regulation.