Abstract
Resistant starches comprise the starch fraction that escapes small intestine (SI) digestion and reaches the colon, where it is fermented by saccharolytic bacteria that produce beneficial postbiotics. Moreover, slowly digestible starches lower glycemic index and may promote satiety. The objectives of this study were to assess whether diets having increased RS perturbed fasting levels of satiety hormones in dogs. Diets with three levels of resistant starch (RS type II) were produced via extrusion at three levels of mechanical energy. Nine male and 15 female adult Beagle dogs were fed the low, medium and high RS foods in a 3x3 Latin square design (n = 24). The study was approved by IACUC at Hill’s Pet Nutrition (# 883.0.0.0). Fasting blood was collected in the morning on days 27 and 28 of each period, and serum was separated and frozen at -70°C until analysis. Satiety hormones were measured by ELISA. Data was first converted to natural log to approximate normal distribution and then analyzed as a mixed model by the GLIMMIX procedure from SAS (v 9.4) with diet as fixed effect and dog and period as random effects. Ghrelin, gastric inhibitory polypeptide (GIP), glucagon-like peptide 1 (GLP-1), glucagon, leptin, pancreatic polypeptide (PP) and peptide YY (PYY) were not different across treatments likely due to the fasting state of dogs. Surprisingly, only insulin increased with higher RS consumption. It is possible that more propionate (not measured) was produced in the colon of dogs fed the high RS diet, which went through gluconeogenesis in the liver and resulted in a change in the time of glucose entering the blood stream. This could explain the insulin increase during fasting, but needs to be verified by measurement of fecal SCFA. Future research should explore the effect of type II RS on satiety hormones at multiple time points postprandial.
PSVI-20 The Effect of Resistant Starch Type II on Satiety Hormones of Fasting Dogs
