Research Advances in Mechanisms of Probiotics for Improvement of Cognitive Impairment

Driven by the global intensification of population aging, the prevalence of neurodegenerative diseases—principally Alzheimer’s disease and its prodromal stage mild cognitive impairment—has escalated continuously, evolving into a critical public health challenge. Aligned with the objectives of the “Healthy China 2030” Planning Outline regarding nutritional interventions, there is an increasingly urgent need to investigate the multifactorial interactions involving gut dysbiosis, neuroinflammation, and the dysfunction of the microbiota-gut-brain axis. In light of the efficacy limitations associated with conventional pharmacological therapies, probiotic-based dietary strategies have emerged as a focal point for mitigating cognitive impairment, owing to their high safety and good tolerability. The specific molecular targets and underlying regulatory mechanisms involved in the amelioration of cognitive impairment by probiotics were systematically elucidated, and their mechanisms of action, including the improvement of metabolite levels, regulation of immune and inflammatory responses, modulation of endocrine signaling pathways, and mediation of vagal nerve conduction, were emphatically discussed. Furthermore, the practical limitations and challenges inherent in probiotic-mediated cognitive interventions were explored. Current applications of probiotic intervention remain constrained by bottlenecks, including the high heterogeneity of clinical evidence, the lack of standardized strain formulations, and insufficiently developed safety assessment frameworks. This study aimed to improve the theoretical foundation for the neuroprotective properties of probiotics as functional food components, provide a scientific basis for the development of novel and precision-regulated food formulations, and ultimately provide a theoretical framework and scientific evidence for supporting the high-value application of auxiliary dietary interventions in addressing the societal challenges posed by an aging population.