Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis

INTRODUCTION: Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults. METHODS: We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population. RESULTS: Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ES(WMD) = −0.56, 95% CI: −0.72, −0.39; p < 0.001, and ES(SMD) = −0.50, 95% CI: −0.66, −0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ES(WMD) = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ES(SMD) = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ES(WMD): 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ES(WMD): 1.48; 95% CI: 0.31, 2.65, p = 0.013; I(2) = 51.7%, p = 0.043). DISCUSSION: Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.