Dietary incorporation of whey protein isolate and galactooligosaccharides exhibits improvement in glucose homeostasis and insulin resistance in high fat diet fed mice.

Abstract

This study was planned to investigate the effectiveness of the whey protein isolate (WPI) of high purity and a galactooligosaccharides (GOS) preparation on glucose homeostasis and insulin resistance in high fat diet (HFD) (45.47% energy from fat) fed conditions in C57BL/6J mice. Fasting blood glucose level, serum insulin, and glucagon-like peptide-1 (enzyme-linked immunosorbent assay) were measured; also, homeostasis model assessment of insulin resistance (HOMA-IR) was determined in different treatment groups. mRNA expression of gluconeogenesis genes in liver and small intestine tissues was analyzed by quantitative real time-polymerase chain reaction. Dietary incorporation of WPI and GOS was observed to significantly resist (P < 0.001) the HFD-induced increase in blood glucose levels indicating a mitigating effect on glycemic load. It is important to note that no additive effects of administration of WPI and GOS could be observed. The administration of WPI and GOS exhibited maximum resistance (37.8%) to the rise in insulin level. Thus, the resistance to the increase in HOMA-IR was also noticed on the dietary incorporation of two functional ingredients . The positive effects on mRNA expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase could be detected in liver only. Both types of functional components exhibit potential to improve glucose homeostasis under HFD fed conditions. Resistance to HFD-induced hyperinsulinemia and HOMA-IR is also recorded .