Low-fat cheese ameliorates glucose intolerance and normalizes insulin secretion in a rat model of type 2 diabetes by promoting β-cell recovery

We aimed to determine if cheese could reduce glucose intolerance in aged rats with overt type 2 diabetes (T2D). Male SpragueDawley rats treated with high-fat diet (HFD) and streptozotocin (STZ) to elicit T2D were hyperglycemic. One week after STZ injection, low-fat (LOW) or regular-fat (REG) cheese was provided for 5 weeks and compared with T2D and low-fat diet reference (REF) groups. Food intake and weight gain were similar in all groups. Oral glucose tolerance tests revealed glucose intolerance in T2D rats that was partially ameliorated by LOW but not REG. Insulin secretion during the oral glucose tolerance test was impaired in T2D and REG at 10 min (p < 0.05) but the iAUC was highly variable in all groups and statistical differences were not detected (p > 0.05). beta-cell mass and pancreatic insulin content in T2D and REG were 50% lower than REF (p < 0.05), whereas LOW was not significantly different. Although isolated islets from all groups responded to glucose, the absolute amount of insulin secreted by T2D and REG was markedly reduced compared with REF, while LOW islets had relatively normal secretion. In conclusion, LOW but not REG cheese enhanced beta-cell recovery from HFD/STZ treatment that led to amelioration of glucose tolerance within 5 weeks.