Glucose absorption from maltotriose and glucose oligomers in the human jejunum

Abstract

The jejunal absorption of glucose from (1-4)-linked glucose oligomers including maltotriose has been compared with that from free glucose and sucrose in normal subjects. A steady-state perfusion technique in vivo was used to study proximal jejunal assimilation of isotonic sugar-saline solutions isocaloric with 140 mmol/l glucose. Endogenous alpha-amylase was excluded from the test segment by proximal balloon occlusion. The glucose oligomer mixture consisted mainly of maltotriose, maltotetraose, maltopentaose and maltoheptaose. Glucose absorption was significantly faster from maltotriose alone and from the glucose oligomer mixture than from 140 mmol/l glucose controls, whereas glucose absorption from 70 mmol/l sucrose was similar to that from 70 mmol/l glucose plus 70 mmol/l fructose. Hydrolysis in vivo of maltotriose, the oligomer mixture and sucrose were similar, indicating that capture of glucose released by brush border sucrose hydrolysis was less efficient than that associated with (1-4)-linked oligomer hydrolysis. This suggests that the stoichiometric relationship of the active hydrolysis sites for sucrose to the glucose transport system is less advantageous than that of active sites for maltose hydrolysis. Hydrolysis of oligomers larger than maltohexaose may be rate limiting for glucose absorption in the absence of luminal amylase activity.

Safety assessment of γ-cyclodextrin

“…Ingested c-CD is rapidly and essentially completely digested by salivary and pancreatic amylase to products which also result from the digestion of starch and linear dextrins. Glucose is the only absorbed product of this digestive process (Jones et al, 1987). The absorption by passive diffusion of intact [ 14 C]c-CD is very low (<0.02%) (De Bie et al, 1998).…”

Water and Solute Absorption From Carbohydrate-Electrolyte Solutions in the Human Proximal Small Intestine: A Review and Statistical Analysis

“…Glucose is absorbed faster from maltose, maltotriose, oligomer mixtures, and glucose polymers than free glucose (Daum, Cohen, McNamara, & Finberg, 1978;Jones, Higgins, & Silk, 1987). Total CHO absorption from a sucrose-electrolyte solution is significantly greater than glucose absorption from a glucoseelectrolyte solution (Patra, Mahalanabis, & Jalan, 1982).…”

The sports drink as a functional food: formulations for successful performance

“…This results in an effective loss of body water and will exacerbate any pre-existing dehydration. Other sugars, such as sucrose (Spiller et al 1982) or glucose polymers (Jones et al 1983(Jones et al , 1987 can be substituted for glucose without impairing glucose or water uptake, and may help by increasing the total transportable substrate without increasing osmolality. In contrast, isoenergetic solutions of fructose and glucose are isosmotic, and the absorption of fructose is not an active process in man; it is absorbed less rapidly than glucose and promotes less water uptake (Fordtran, 1975).…”