Efficacy of inulin supplementation in improving insulin control, HbA1c and HOMA-IR in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

Type 2 diabetes mellitus is a chronic disease that occurs among the general population. The insulin-lowering and homeostasis model assessment of insulin resistance-improving effects of inulin are unconfirmed. We conducted this meta-analysis to examine the efficiency and safety of inulin for improving insulin control, homeostasis model assessment of insulin resistance and HbA1c in patients with type 2 diabetes mellitus. We searched the Web of Science, PubMed, Embase and Cochrane Library databases for relevant articles published before June 1, 2019. In total, 225 randomized controlled trials regarding the efficiency of inulin for the treatment of type 2 diabetes mellitus compared to the efficacy of placebo or other treatments were examined. According to the inclusion and exclusion criteria, 9 trials with a total of 661 participants were included. We concluded that inulin supplementation can significantly improve fasting plasma glucose (SMD = -0.55, 95% CI -0.73 to -0.36, p = 0), HOMA-IR (SMD = -0.81, 95% CI -1.59 to -0.03, p = 0.042) and HbA1c (SMD = -0.69, 95% CI -0.92 to -0.46, p = 0). Further subgroup analyses revealed a significant role of inulin supplementation for treatment durations ≥8 weeks (p = 0.038 for insulin, p = 0.002 for HOMA-IR, p = 0.032 for FPG, p = 0 for HbA1c).