Absorption of Nutrients Is Only Slightly Reduced by Supplementing Enteral Formulas with Viscous Fiber in Miniature Pigs

Abstract

Viscous polysaccharides reduce intestinal absorption of glucose and diminish postprandial hyperglycemia. However, it is unknown whether viscous fiber also inhibits absorption of nutrients under conditions of enteric feeding. Therefore, we measured the absorption rates of nutrients in miniature pigs by perfusing a 150-cm length of jejunum with 8.37 kJ/min of the three following enteral diets: an isoosmotic oligomeric diet (1670 kJ/L), a hyperosmotic oligomeric diet and an isoosmotic polymeric diet (both 3350 kJ/L). The diets were supplemented with guar gum from 0 to 4.4 g/L. With the three guar-free diets, the mean absorption rate of energy was 5.2 +/- 0.32 kJ/min, corresponding to 62% of the energy infused. Absorption rates of carbohydrate, protein, fat and energy linearly declined as concentrations of guar or the logarithm of chyme viscosity increased. Due to modulations in viscosity, the inhibitory effects of guar were significantly different among the three diets. With the isoosmotic and hyperosmotic oligomeric and the polymeric diets, the addition of 1 g guar/L diminished the absorption of energy by 9.7, 6. 6 and 3.7%, respectively. The strong inhibitory effect on nutrient absorption with the isoosmotic oligomeric diet was caused by an increase in chyme viscosity due to water absorption. With the hyperosmotic oligomeric and the polymeric diets, the chyme viscosity and thus inhibitory effects on absorption were diminished by water secretion and the concomitant infusion of pancreatic enzymes. Results indicate that the addition of small amounts of guar gum to enteral diets of high energy density exerts only small effects on absorption of nutrients.

Contribution of plasma proteins to splanchnic and total anabolic utilization of dietary nitrogen in humans

“…The model predictions in terms of the gastric-emptying half-time, flow rates of absorption, and net absorption from the different intestinal lumen compartments are strikingly in line with current knowledge of gastrointestinal kinetics (3,8,21,29,60), as summarized in Table 4. For instance, ϳ80% of dietary N absorption was predicted to occur in the upper part of the gastrointestinal tract, in line with the idea that dietary N is principally absorbed in the proximal part of the small intestine (28,29,60).…”

“…In humans, a compartmental analysis such as the one accomplished here would enable assessment of the d Half-time of gastric emptying of proteins after a mixed-protein meal of 1,840 kJ in humans (with a ratio of nutrients close to that of our meal: 51% carbohydrate; 15% protein; 35% fat) (8). e Mean absorption rate of protein along a 150-cm-long segment of jejunum after infusion into the jejunal segment of an enteral diet (50% carbohydrate; 20% protein; 30% fat) at a rate of 68 mg protein/min in miniature pigs (21).…”

Increasing the viscosity of the intestinal contents stimulates proliferation of enterotoxigenicEscherichia coliandBrachyspira pilosicoliin weaner pigs

“…Previously, other studies have shown that increasing the viscosity of diets for grower pigs results in corresponding increases in the viscosity of the small intestinal contents for several hours after feeding (Cherbut et al 1990;Ellis et al 1995;Ehrlein & Haas-Deppe, 1998;Ehrlein & Stockmann, 1998).…”

Hyperosmolarity in the small intestine contributes to postprandial ghrelin suppression

“…A second dietary approach to stimulate small intestinal hyperosmolarity could be to enhance levels of macronutrient polymers (i.e., proteins and carbohydrates), which during digestion produce many transiently osmotically active oligo-and monomers (23,65). One observation supporting this concept is that weight loss after a low-fat, high-carbohydrate diet is not associated with the usually observed compensatory rise in ghrelin (88).…”