Effect of viscosity and fermentability of purified non‐starch polysaccharides (NSP) on kinetics of net glucose and short chain fatty acids (SCFA) portal flux and insulin secretion in porto‐arterial catheterized pigs

Abstract

The NSP may lower glycemic and insulin responses, but specific contributions of viscosity and fermentability are unknown. Thus, the effects of NSP on net nutrient portal flux and insulin responses were studied in 4 pigs with 2 catheters [portal vein, carotid artery] and 1 blood flow probe [portal vein]. Semi‐purified [cornstarch, casein] diets supplemented with 5% purified NSP sources were fed in a 2 (low, high viscous; V) × 2 (low, high fermentable; F) factorial arrangement using: low V, low F cellulose (CEL1), high V, low F carboxymethylcellulose (CMC), low V, high F cellulose (CEL2), and high V, high F oat β‐glucan (HVG). Blood was sampled for 12 h postprandially and net nutrient portal flux and insulin secretion were calculated from plasma portal‐arterial differences × flow. Blood flow, portal and carotid glucose and net glucose portal flux peaked at 45 min after feeding (P<0.001) and were not affected by NSP. However, fermentable NSP (CEL2 and HVG) increased (P<0.05) net glucose portal flux 46% over 12 h postprandially. Insulin secretion was 44% lower (P<0.05) for viscous than non viscous NSP. The CEL2 and HVG diets increased (P<0.05) net SCFA portal flux for propionate and butyrate 48%, indicating increased colonic fermentation. In conclusion, viscosity of NSP reduced insulin secretion and fermentable NSP increased net portal flux of glucose, propionate, and butyrate.Grant Funding Source: ALMA, Danisco, and Alberta Pulse Growers