Starch chemistry affects kinetics of glucose absorption and insulin response in swine

Starch chemistry may affect kinetics of nutrient absorption and insulin secretion. The objective was to define the glucose absorption kinetics and insulin response in swine to diets containing starch with a wide range in chemistry and in vitro digestion patterns. Diets tested contained purified starch (700. g/kg diet) ranging from rapid to slow digestible starch [maximal rate of in vitro glucose release (%)/min: 1.53, rapid; 0.94, moderate rapid; 0.37, moderate slow; and 0.14, slow]. In vitro rate of starch digestion was characterized using an assay modified after Englyst et al. (2003). In vivo kinetics were determined using four pigs (35.0 ± 0.2 kg) surgically fitted with catheters in the portal vein and carotid artery and a portal blood flow probe. Pigs were fed for 7-d periods in a 4 × 4 Latin square. On d 7, blood was collected for 12 h postprandially. Net glucose absorption differed (P<0.05) among diets at 45, 90, 120, and 150. min postprandial. Cumulative glucose absorption up to 12 h did not differ among rapid, moderate rapid, and moderate slow digestible starch diets, but these diets had a higher (P<0.05) cumulative glucose absorption than slow digestible starch diets. In addition, portal plasma insulin and C-peptide release peaked at 30. min postprandial and differed (P<0.05) among diets at 30 and 60. min postprandial, except between moderate rapid and moderate slow digestible starch diets. In conclusion, starches with a wide difference in in vitro starch digestion affect kinetics of glucose absorption and insulin response in swine. © 2010 Elsevier B.V.