The Effects of Supplementation with Probiotic on Biomarkers of Oxidative Stress in Adult Subjects: a Systematic Review and Meta-analysis of Randomized Trials.

Previous studies have supposed that probiotic supplementation led to a positive effect on different health outcomes. Furthermore, several studies indicated that probiotics supplementation improved antioxidant status, while some studies did not indicate these effects. Hence, current systematic review and meta-analysis study was conducted to determine the effect of probiotic supplementation on some oxidative stress biomarkers among adult subjects. We searched four electronic databases PubMed, SCOPUS, ISI Web of Science, and the Cochrane Library till November 2017. Clinical trials that compared the effects of probiotic supplementation with the control group were included. A random-effect model was used to pool weighted mean difference (WMD). Finding of 11 included studies (n = 577) indicated that probiotic supplementation increased total antioxidant capacity (TAC) (WMD 77.30 mmol/L; 95% confidence interval [CI] 2.60, 152.01; I2 = 88.3%) and reduced malondialdehyde (MDA) (WMD - 0.31 μmol/L; 95% CI - 0.54, - 0.08; I2 = 71.5%) significantly compared to the control group. However, its effects on glutathione (GSH) was not significant (WMD = 19.32 μmol/L; 95% CI - 18.70, 57.33; I2 = 64.9%). The current meta-analysis revealed that probiotic supplementation may result in increasing TAC and lowering MDA, which improve antioxidant status. However, due to high heterogeneity, findings should be interpreted with caution. Further investigations are required to elucidate the effect of supplementation with probiotics on biomarkers of antioxidants.