Effect of probiotics on glucose metabolism in patients with type 2 diabetes mellitus: A meta-analysis of randomized controlled trials

Objective: Our aim was to investigate the effects of probiotics on glucose metabolism in patients with type 2 diabetes mellitus using a meta-analysis of randomized, controlled trials. Materials and methods: Online databases Embase, Web of Science, and PubMed were searched until August 2014 to identify eligible articles. Finally, 7 trials were included.
Results: Probiotic consumption significantly changed fasting plasma glucose (FPG) by -15.92 mg/dL (95% confidence interval [CI], -29.75 to -2.09) and glycosylated hemoglobin (HbA1c) by -0.54% (95% CI, -0.82 to -0.25) compared with control groups. Subgroup analysis was conducted to trials with non-yogurts control. Meta-analysis of trials with multiple species of probiotics found a significant reduction in FPG (weighted mean difference [WMD]: -35.41 mg/dL, 95% CI: -51.98 to -18.89). The duration of intervention for ≥8 weeks resulted in a significant reduction in FPG (WMD: -20.34 mg/dL, 95% CI: -35.92 to -4.76). Subgroup analysis of trials with species of probiotics did not result in a significant meta-analysis effect. Furthermore, the duration of intervention <8 weeks did not result in a significant reduction in FPG. The results also showed that probiotic therapy significantly decreased homeostasis model assessment of insulin resistance (HOMA-IR) and insulin concentration (WMD: -1.08, 95% CI: -1.88 to -0.28; and WMD: -1.35 mIU/L, 95% CI: -2.38 to -0.31, respectively).
Conclusions: The present meta-analysis suggests that consuming probiotics may improve glucose metabolism by a modest degree, with a potentially greater effect when the duration of intervention is ≥8 weeks, or multiple species of probiotics are consumed.