OBJECTIVES: Gastrointestinal hormones, such as glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide, and peptide YY (PYY) are important for reducing malnutrition at older ages because they are related to assimilation and feeding behavior. Medium-chain triacylglycerol (MCT) ameliorates metabolic symptoms and frailty in adults
however, whether it has the same effect in old age is unknown. To address this, we examined the changes in insulin and gastrointestinal hormones in aged Brd4 (+/-) mice exhibiting symptoms of old age. RESEARCH METHODS AND PROCEDURES: Aged male wild-type and Brd4 (+/-) mice were fed a long-chain triacylglycerol (LCT)- or MCT diet. Feeding, blood glucose, and plasma active GLP-1 protein concentrations were determined at 9 weeks using a meal tolerance test, and those gastrointestinal hormone genes were determined at 10 weeks. RESULTS: The liver and stomach weights and mRNA expression of Gcg (encodes GLP-1 protein) and Pyy in the colon were lower in LCT-fed Brd4 (+/-) mice than those in LCT-fed wild-type mice
these were restored by the MCT diet. The blood concentration of active GLP-1 protein at 15 and 30 minutes postload was higher in MCT-fed Brd4 (+/-) mice than that in those fed an LCT diet. CONCLUSIONS: Aged Brd4 (+/-) mice showed lower mRNA expression of Gcg and Pyy genes, and active GLP-1 protein secretion in the blood, which were as restored and enhanced with MCT feeding.