Although oxidative agents such as free radicals can fight pathogens, an imbalance of oxidants to anti-oxidant activity can lead to harmful effects in our body known as oxidative stress. Various cellular organelles produce oxidative agents as well as anti-oxidants. The main oxidative stressors are classified under the free radical species; reactive oxygen species and reactive nitrogen species. On the other hand, super oxide dismutase, glutathione peroxidase, catalase and Glutathione are the main enzymatic mechanisms against oxidations. Gut microbiota with trillions of beneficial bacteria plays a considerable role in the production of anti-oxidants. Emerging evidence indicates an association between damaged intestinal flora and oxidative stress. Probiotics as beneficial bacteria are shown to restore damaged intestinal microbiota. Extensive evidence indicates the helpful effects of probiotics on the balance of anti-oxidant/oxidative agents. Since oxidative stressors play an important role in the development of some neurological disorders, intestinal microbiota modification and probiotic supplements are considered as suggested treatments to prevent or even relieve symptoms in the brain diseases. This review considers the beneficial effect of the gut and probiotic bacteria in either fighting the oxidative factors or producing the anti-oxidative biomarkers. CLICK TO REVIEW