A systematic review and meta-analysis of the probiotics and synbiotics effects on oxidative stress

We performed a comprehensive search of medical bibliographic databases to identify interventional studies reporting the effect of probiotics (or synbiotics) supplementation on biomarkers of oxidative stress. Twenty seven articles that included 1363 subjects (709 cases and 699 controls) were included to our analyses. Oxidative stress parameters levels, including total antioxidant capacity (TAC) (0.31 mmol/L, 95% CI: 0.13-0.50, P < 0.001), glutathione (GSH) (SMD: 0.44 mu mol/L, 95% CI: 0.26-0.62, P < 0.001), superoxide dismutase (SOD) (SMD: 0.48 U/mg, 95% CI: 0.16-0.81, P = 0.004) and nitric oxide (NO) (SMD: 0.57 mu mol/L, 95% CI: 0.19-0.94, P = 0.003) were higher in probiotics (or synbiotics) group compared to controls. Moreover, malondialdehyde (MDA) (SMD = -0.45 mu mol/L, 95%Cl = -0.63 to -0.26, P < 0.001) level was lower than controls. Probiotics and synbiotic supplementation improve antioxidant resistance and increase the amount of antioxidant enzymes in the body.