Edwards C A, Johnson I T, Read N W
Clinical Research Unit, Royal Hallamshire Hospital, Sheffield, UK.
Eur J Clin Nutr. 1988 Apr;42(4):307-12.
Viscous polysaccharides such as guar gum delay absorption probably by impairing the access of luminal contents to the absorptive epithelium. Measurements of the electrical resistivity of saline solutions were carried out to determine if guar gum (0.5, 0.75 and 1 per cent w/v), in concentrations which impaired absorption in vitro, delayed diffusion of solutes or inhibited convection of luminal contents. Our results indicated that guar had no effect on the mobility of ions in a completely unstirred solution but delayed the time taken for saline solutions of different resistivity to achieve complete mixing, when they were brought into contact inside a vessel, which was rotated at a constant speed. The time taken to achieve complete mixing was directly related to the viscosity of the guar solutions. The effect of intestinal contraction on the absorption of glucose was simulated in an in vitro model, consisting of a length of dialysis tubing, alternately contracted at each end. Movement of glucose out of the dialysis tubing was increased by increasing the rate of contraction. The incorporation of guar gum into the solution prevented the rise in glucose uptake produced by increasing the rate of contraction. These effects suggest that guar probably reduces absorption by resisting the convective effects of intestinal contractions.
粘性多糖（如瓜尔胶）可能通过阻碍管腔内容物与吸收上皮的接触来延迟吸收。进行盐溶液的电阻测量，以确定在体外损害吸收的浓度（0.5%、0.75%和1%w/v）的瓜尔胶是否会延迟溶质扩散或抑制管腔内容物的对流。我们的结果表明，瓜尔胶在完全不搅拌的溶液中对离子迁移率没有影响，但当不同电阻率的盐溶液在以恒定速度旋转的容器内接触时，瓜尔胶会延迟它们达到完全混合所需的时间。达到完全混合所需的时间与瓜尔胶溶液的粘度直接相关。在一个体外模型中模拟了肠道收缩对葡萄糖吸收的影响，该模型由一段透析管组成，两端交替收缩。通过增加收缩速率，葡萄糖从透析管中的移出增加。将瓜尔胶加入溶液中可防止因增加收缩速率而导致的葡萄糖摄取增加。这些效应表明，瓜尔胶可能通过抵抗肠道收缩的对流效应来减少吸收。
