Ohta A, Taguchi A, Takizawa T, Adachi T, Kimura S, Hashizume N
Nutritional Science Center, Meiji Seika Kaisha Ltd., Saitama, Japan.
Int J Vitam Nutr Res. 1997;67(1):55-61.
Soluble dietary fibers include an alginate which reduces the postprandial glycaemic response. We speculated that the cause of the reduction of alginate on the glycaemic response is the gel formation of alginate with dietary calcium in the stomach. The aim of the present study was to confirm our hypothesis and to examine the effect of the sugar composition of alginates on the glycaemic response and the effect of continuous feeding of alginate-containing diet to rats. Diabetic rats were made by injecting streptozotocin (STZ) intravenously. These rats were fed 5 g of the experimental diet with or without sodium alginate and with or without calcium after overnight fasting. In the rats fed the diet containing both alginate and calcium, the postprandial glycaemic response was lower than in the rats fed other diets and gastric contents were retained as gel form. Three beta-d-mannuronic acid (M) to alpha-l-guluronic acid (G) (ratios (M/G 0.5, 1.3, 2.1) of alginates were not associated with the acute glycaemic response in STZ rats. Then, we fed normal rats with an alginate-free or one of three respective alginate-containing diets for 4 weeks. During the first 2 weeks of the feeding period, the total amount of food intake of rats fed the G-rich alginate diet was smaller than that of rats in the other dietary groups. Moreover, the weight of the dorsal abdominal adipose tissue of rats given the G-rich alginate diet was the lowest among the dietary groups. We conclude that the reductive effect of alginate feeding on the postprandial glycaemic response was not caused only by their inherent viscosity, but also by gel formation with dietary calcium in the stomach. Moreover, it is necessary to pay attention to the M/G ratio of alginates for estimating their physiological effect.
可溶性膳食纤维包括一种能降低餐后血糖反应的藻酸盐。我们推测藻酸盐降低血糖反应的原因是其在胃中与膳食钙形成凝胶。本研究的目的是证实我们的假设，并研究藻酸盐的糖组成对血糖反应的影响以及向大鼠持续投喂含藻酸盐饮食的效果。通过静脉注射链脲佐菌素（STZ）制备糖尿病大鼠。这些大鼠在禁食过夜后，分别喂食5克含或不含海藻酸钠以及含或不含钙的实验性饮食。在喂食同时含有藻酸盐和钙的饮食的大鼠中，餐后血糖反应低于喂食其他饮食的大鼠，并且胃内容物以凝胶形式留存。三种藻酸盐的β-D-甘露糖醛酸（M）与α-L-古洛糖醛酸（G）的比例（M/G分别为0.5、1.3、2.1）与STZ大鼠的急性血糖反应无关。然后，我们给正常大鼠喂食不含藻酸盐或三种含藻酸盐饮食之一，持续4周。在喂食期的前2周，喂食富含G的藻酸盐饮食的大鼠的食物摄入总量低于其他饮食组的大鼠。此外，在各饮食组中，喂食富含G的藻酸盐饮食的大鼠的腹背脂肪组织重量最低。我们得出结论，投喂藻酸盐对餐后血糖反应的降低作用不仅是由其固有粘度引起的，还与在胃中与膳食钙形成凝胶有关。此外，在评估藻酸盐的生理作用时，有必要关注其M/G比例。
