Effects of prebiotics on postprandial GLP-1, GLP-2 and glucose regulation in patients with type 2 diabetes: A randomised, double-blind, placebo-controlled crossover trial

AIMS: We aimed to investigate the effect of prebiotic inulin-type fructans versus a control supplement on postprandial levels of glucagon-like peptide-1 and -2 (GLP-1 and -2), glucose, and insulin in patients with type 2 diabetes.

METHODS: Adult men and women with type 2 diabetes were randomised in a double-blind, placebo-controlled crossover study. The study participants received 16 g/d inulin-type fructans and 16 g/d control supplement (maltodextrin) for six weeks each in two phases separated by a four weeks washout. A standardised mixed meal test was performed before and after each intake period. The primary endpoint was changes in the GLP-1 response, and secondary endpoints were GLP-2, glucose and insulin responses. Data were analysed using mixed model analysis.

RESULTS: A total of 29 participants were included in the study. Differences between and within the two treatments in estimated area under the curves were not significant. Yet, the predicted means for meal induced GLP-1 response in plasma showed a 4.8% decline after the prebiotic treatment and an 8.6% increase after the control treatment (difference in changes between the treatments, p < 0.001). Fasting or postprandial glucose, insulin or GLP-2 levels were not changed.

CONCLUSIONS: Our findings do not support that inulin-type fructans improve incretin responses or glucose-regulations in this population.