Effects of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles: a systematic review and meta-analysis of randomized controlled trials

Objectives: Previous studies have evaluated the effects of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles among diabetic patients. However, the results were inconsistent. Study design: Systematic review and meta-analysis. Methods: A systematic searching from PubMed, ISI Web of Science, Embase, and Cochrane Central was conducted to identify high-quality clinical trials investigating the effect of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles [including fasting blood glucose (FBG), hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR)] up to December 2020. Subgroup analyses by types or durations of probiotic/prebiotic/synbiotic supplementation were con-ducted to investigate the different effects among different populations. Results: A total of 39 trials with 3517 participants were included in the final analyses. Among patients with type II diabetes (T2DM), the summarized standardized mean differences (SMDs) and 95% confi-dential intervals (95% CIs) of FBG, HbA1c, and HOMA-IR were-0.30 (95% CI:-0.65 to 0.05),-0.59 (95% CI:-0.88 to-0.30), and-0.68 (95% CI:-1.13 to-0.23), respectively. Among patients with gestational diabetes (GDM), the summary SMDs of FBG, HbA1c and HOMA-IR were-0.67 (95% CI:-1.23 to-0.11),-0.24 (95% CI:-0.57 to 0.08), and-1.06 (95% CI:-1.72 to-0.40), respectively. Similar im-provements in blood glucose profiles were also found among persons with prediabetes or gestational woman with normal glucose, but not among patients with type I diabetes. Subgroup analyses showed similar results of probiotic supplementation for patients with T2DM and probiotic/synbiotic supple-mentation for patients with GDM. Conclusion: Probiotic/prebiotic/synbiotic supplementation might improve the blood glucose profiles among patients with T2DM/GDM, persons with prediabetes, or gestational woman with normal glucose. Trials with more sophisticated design are needed to validate the results in the future. Systematic review registration: PROSPERO CRD42020161975. (c) 2022 Published by Elsevier Ltd on behalf of The Royal Society for Public Health.

Automated summary

This study conducted a systematic review and meta-analysis, finding that probiotic/prebiotic/synbiotic supplementation may improve blood glucose profiles among patients with diabetes, prediabetes, and pregnant women with gestational diabetes.