Postprandial glycaemic and insulinaemic responses to GM-resistant starch-enriched rice and the production of fermentation-related H2 in healthy Chinese adults.

Consumption of resistant starch (RS)-enriched foods is associated with decrease in the postprandial glycaemic and insulinaemic responses, accompanied by the production of fermentation-related gases in the large bowel. The present study aimed to determine the postprandial glycaemic and insulinaemic responses to the GM RS-enriched rice and the fermentation-related production of H2 in young and healthy Chinese adults. A total of sixteen young adults (nine men and seven women) were recruited and divided into three groups. Their postprandial glycaemic and insulinaemic responses to 40 g glucose, carbohydrates of RS or wild-type (WT) rice were tested by a crossover model with a washout period of 7 d. The concentrations of blood glucose and insulin as well as breath H2 were measured before and after food intake. Although the mean concentrations of fasting blood glucose, insulin and breath H2 were similar, consumption of the RS rice significantly decreased the values of glycaemic index (GI) and insulin index (II), as compared with the intake of WT rice (48.4 (sem 21.8) v. 77.4 (sem 34.9) for GI, 34.2 (sem 18.9) v. 54.4 (sem 22.4) for II, P < 0.05), respectively. Conversely, intake of the RS rice meal significantly elevated the concentrations of breath H2, as compared with WT rice (38.9 (sem 17.6) v. 10.5 (sem 3.7) parts per million for peak levels of breath H2, P < 0.05) through a period of 16-h tests. Consumption of the GM RS-enriched rice meal decreased the postprandial glycaemic and insulinaemic responses and promoted RS fermentation-related production of H2 in the large bowel of young and healthy Chinese adults.