Introduction: Cognitive impairments resulting from oxidative stress and chronic neuroinflammation are significant contributors to the onset and progression of neurodegenerative diseases, including Alzheimer’s and Parkinson’s. Excessive production of reactive oxygen species (ROS) and diminished activity of endogenous antioxidant systems lead to neuronal damage, synaptic dysfunction, and deficits in memory and learning. The gut-brain axis and gut microbiome play crucial roles in regulating inflammatory and antioxidant responses in the central nervous system. Probiotics, through modulation of gut microbiota, can exert significant neuroprotective effects and potentially improve cognitive functions.
Methods: This review systematically examines published studies investigating the effects of probiotics on oxidative stress, neuroinflammation, antioxidant enzyme activity, memory performance, and synaptic structure. Data were retrieved from PubMed, Google Scholar, and Scopus databases, encompassing both animal and human studies. Selected articles were analyzed to elucidate the molecular and behavioral mechanisms by which probiotics mitigate cognitive dysfunction.
Results: Research by Bahareh Pakpour and colleagues demonstrated that probiotic administration enhances the activity of key antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GPx), while reducing the levels of pro-inflammatory cytokines, such as TNF-α and IL-6, in brain tissue. These effects contribute to decreased lipid peroxidation and oxidative stress, thereby preserving neuronal integrity and synaptic structure.
Studies by Majid Noaeian revealed that probiotics improve memory and learning in animal models by inhibiting NF-κB-mediated inflammatory pathways and activating Nrf2-dependent antioxidant signaling. Additionally, research by Dr. Tajabadi indicated that combining probiotics with antioxidant-rich diets exerts synergistic neuroprotective effects, potentially delaying the progression of neurodegenerative processes.
Other reviewed studies indicate that probiotics modulate neurotrophin metabolism, reduce oxidative stress and inflammation, and maintain synaptic connectivity, collectively supporting cognitive enhancement. These findings suggest that probiotics can serve as an adjunctive therapeutic strategy in managing memory disorders and improving overall cognitive performance.
Conclusion: Current evidence highlights probiotics as a promising intervention for preventing cognitive dysfunction associated with oxidative stress and neuroinflammation. Probiotic supplementation promotes neuronal health, preserves synaptic architecture, attenuates neuroinflammation, and enhances memory and learning abilities. These findings support the inclusion of probiotics as a potential adjunct in the prevention and management of cognitive impairments and neurodegenerative conditions.
Keywords: Oxidative Stress , Gut Microbiome, Neuroinflammation, Memory, Gut-Brain Axis