EFFECT OF PARTIALLY DEPOLYMERIZED GUAR GUM ON ACUTE METABOLIC VARIABLES IN PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES

Fourteen patients with non-insulin-dependent diabetes (NIDDM) attended the study centre on 4 mornings separated by at least 3 days, to recei ve in random order 75 g carbohydrate breakfast meals of control or gua r breads with jam and butter. Guar gum flours of low, medium, and high molecular weight (MW) were incorporated into wheat bread rolls to pro vide 7.6 g guar per meal. Venous blood samples were taken via an indwe lling cannula in a forearm vein at fasting and at eight postprandial t imes and then analysed for blood glucose, plasma insulin, C-peptide, a nd gastric inhibitory polypeptide (GIP). Guar gum bread significantly reduced the postprandial rise in blood glucose, plasma insulin, and, e xcept for bread containing low MW guar gum, plasma GIP levels compared to the control. Thus, the partial depolymerization of guar gum does n ot diminish its physiological activity. No reductions in postprandial plasma C-peptide levels were seen after any of the guar bread meals. T his suggests that guar gum attenuates the insulin concentration in per ipheral venous blood in patients with NIDDM by increasing the hepatic extraction of insulin.