abstract: Probiotics, traditionally recognized for their role in gastrointestinal health, have recently been investigated for their potential influence on cognitive function through modulation of the gut-brain axis (GBA). This review summarizes the current clinical evidence and mechanistic insights on the role of probiotic interventions in mitigating cognitive decline and enhancing brain function, particularly in older adults and individuals with neuropsychiatric conditions. Cognitive impairments in the elderly, driven by neurodegeneration, vascular compromise, inflammation, and lifestyle factors, present significant challenges to public health systems. Several randomized controlled trials have demonstrated the beneficial effects of specific probiotic strains, such as Bifidobacterium breve A1, Lactiplantibacillus plantarum P8, and multispecies formulations, in improving memory, attention, and emotional regulation in populations with mild cognitive impairment, Alzheimer’s disease, major depressive disorder, and schizophrenia. The cognitive improvements are linked to various mechanisms, including anti-inflammatory and antioxidant activities, modulation of neurotransmitter levels, maintenance of gut barrier integrity, and shifts in gut microbiota composition favoring beneficial taxa. However, not all interventions have yielded significant effects, suggesting strain-specific efficacy and interindividual variability in response. The present study discusses the limitations of existing studies and emphasizes the need for personalized approaches and rigorous, long-term clinical trials. Overall, probiotics show promise as adjunctive agents for preserving cognitive health and managing neurodegenerative and psychiatric disorders via modulation of the microbiota-GBA.
Sivamaruthi et al. (2026) studied this question.