Effects of probiotics on blood glucose, biomarkers of inflammation and oxidative stress in pregnant women with gestational diabetes mellitus: A meta-analysis of randomized controlled trials

Background: The role of probiotics supplementation in gestational diabetes mellitus (GDM) remains controversial. We conducted this meta-analysis to investigate the effects of probiotics on fasting blood glucose (FBG), high-sensitivity C-reactive protein (hs-CRP), total glutathione (GSH), malonaldehyde (MDA) and nitric oxide (NO) levels in pregnant women with GDM. Methods: We systematically searched the Cochrane Library, Embase and PubMed electronic databases up to November 2018. A meta-analysis was then conducted using weighted mean difference (WMD) and 95% confidence interval (CI) as effect measures. Results: A total of 7 studies were enrolled in the final meta-analysis. Data showed that probiotics reduced FBG (WMD: -3.19 mg/d1, 95% CI: -5.55 to -0.82, A=0.008) in pregnant women with GDM. Sub-group analysis suggested that the effect of probiotics on lowering FBG was more significant in patients with a baseline FBG >= 92 mg/dl (WMD: -3.62 mg/dl, 95% CI: -6.64 to -0.60, A=0.019), a duration of probiotic treatment <= 6 weeks (WMD: -3.24 mg/dl, 95% CI: -4.96 to -1.53, A=0.000) and a dose < 6 x 10(9) colony-forming unit (CFU) (WMD: -3.37 mg/dl, 95% CI: -6.64 to -0.10, A=0.043). In addition, probiotics were effective in reducing hs-CRP and MDA in pregnant women with GDM, but had no significant effect on either GSH or NO. Conclusion: This meta-analysis suggests that probiotics supplementation might have a small effect on the reduction of FBG in pregnant women with GDM, and might have certain effects on some biomarkers of inflammation and oxidative stress. However, given the heterogeneity between studies, the results should be interpreted with caution but are worthy of further investigation. (C) 2019 Elsevier Espana, S.L.U. All rights reserved.