The impact of soluble dietary fibre on gastric emptying, postprandial blood glucose and insulin in patients with type 2 diabetes.

Dietary fibre plays an important role in controlling postprandial glycemic and insulin response in diabetic patients. The intake of dietary fibre has been shown to delay the gastric emptying in healthy subjects. The relationship between gastric emptying and postprandial blood glucose in diabetic patients with fibre-load liquids needs to be investigated. To investigate the impact of soluble dietary fibre (SDF) on gastric emptying, postprandial glycemic and insulin response in patients with type 2 diabetes. 30 patients with type 2 diabetes (DM) and 10 healthy subjects (HS) matched for gender and age were randomized to receive SDF-free liquid (500 mL, 500 Kcal) and isoenergetic SDF liquid (oat β-glucan 7.5 g, 500 mL, 500 Kcal) on two separate days based on a cross-over with 6-day wash-out period. Gastric emptying was monitored by ultrasonography at intervals of 30 min for 2 hours. Fasting and postprandial blood was collected at intervals of 30-60 min for 180 min to determine plasma glucose and insulin. Proximal gastric emptying was delayed by SDF-treatment both in DM (p=0.001) and HS (p=0.037). SDF resulted in less output volume in the distal stomach in DM (p<0.05). SDF decreased postprandial glucose (p=0.001) and insulin (p=0.001) in DM subjects. Postprandial glucose (r=-0.547, p=0.047) and insulin (r=-0.566, p=0.004) were negatively correlated with distal emptying of SDF in DM subjects. Distal gastric emptying was delayed significantly in DM subjects with HbA1c levels ≥6.5% (p=0.021) or with complications (p=0.011) by SDF, respectively. SDF improved postprandial glycaemia which was related to slowing of gastric emptying.