The Jejunal Absorption of Glucose Oligomers in the Absence of Pancreatic Enzymes

Abstract

Summary: We compared the absorption of carbohydrate from solutions of glucose oligomers and glucose in jejunal Thiry-Vella fistulae, a preparation deprived of pancreatic secretions. The studies were performed with two concentrations (90 and 360 mg/dl) of both glucose and the glucose oligomers. Carbohydrate absorption from glucose solutions (33.1 × 2.8, 115.9 × 8.9 μg/cm/min) was significantly greater (P < 0.025; P < 0.005) than that from oligomer solutions (26.6 × 2.1 and 92.4 × 9.0 μg/cm/min). Thin-layer analyses of the perfusates demonstrate digestion of oligomers with a chain length up to eleven and suggest digestion of oligomers of even greater chain length. Atrophy of the jejunal mucosa occurred over the course of the study as evidenced by a decrease in the ratio of villous height to crypt depth from 3.8 to 0.3, and by a 80% decrease in the activity of maltase, sucrase, and lactase. Atrophy was accompanied by a significant decline in the absorption of both glucose oligomers (P < 0.005) and glucose (P < 0.01) from the more concentrated solutions but the decrement in absorption of both carbohydrates was similar, glucose oligomers, 79.3 × 19.4 μg/cm/min; and glucose, 69.8 × 14 μg/cm/min (P > 0.20). Water absorption was enhanced by both carbohydrates, but there was no demonstrable difference between solutions of glucose and glucose oligomers. The osmolality of the solutions clearly influenced water absorption (P < 0.025) but failed to effect the absorption of carbohydrates. Speculation: In patients with pancreatic insufficiency, solutions of glucose oligomers with low osmolality may provide an adequate source of calories. Although glucose is better absorbed than glucose oligomers from a short segment of jejunum, the length of the small intestine should be adequate to compensate for this difference.~h~ absorption of the glucose oligomers may be a function of polymer length and therefore studies with subfractions separated according to chain length will demonstrate which oligomers are most efficiently absorbed. such information may provide the theoretical hasis for the construction of an ideal carbohydrate supplement for patients with pancreatic insufficiency.