Impact of wheat and oat polysaccharides provided as rolls on the digestion and absorption processes in the small intestine of pigs

The objective of the present investigation was to study the impact of wheat and oat polysaccharides provided as rolls with contrasting dietary fibre characteristics on ileal digesta and portal and arterial plasma glucose concentrations. The diets were offered as baked rolls to eight pigs fitted with a T-shaped cannula for total collection in a crossover design and to four portal vein- and mesenteric artery-catheterised pigs. Ileal digesta were collected at 2 h intervals during an 8 h sampling period and portal and arterial blood at 10 min intervals from -10 min up to 120 min and then at 30 min intervals up to 240 min post-feeding. There was substantial variation in the flow of ileal digesta during the 8 h sampling period, but the flow was more uniform when feeding the oat rolls compared with the wheat rolls. Carbohydrates were the predominant ileal constituent, with most of them present as non-starch polysaccharides and with starch in both diets almost completely digested at the end of the small intestine. Ingestion of the two diets was followed by a rapid rise in postprandial glucose concentration but with no significant difference in either portal or arterial glucose concentration pattern between the two diets. The recovery of glucose in the portal vein up to 240 min after feeding represented 47-64% of consumed starch. Cellulose, resistant starch and arabinoxylans were almost completely recovered at the ileum, while there was a substantial loss of mixed linkage (1 -> 3)(1 -> 4)-beta-D-glucan. (C) 2007 Society of Chemical Industry.