Bridging Diet and Cognition: Gut Microbiota Modulation as a Preventive Strategy for Mild Cognitive Impairment via the Microbiota-Gut-Brain Axis

Mild cognitive impairment (MCI) is widely recognized as a transitional stage between normal aging and dementia, posing a substantial public health burden. Unlike dementia, MCI may be stabilized or even reversed with timely intervention. However, no approved pharmacological treatments are currently available for MCI. Thus, safe and feasible dietary strategies may offer a promising approach to delaying cognitive decline. This review outlines the association between MCI and gut microbiota (GM), focusing on the role of microbial metabolites in regulating brain function via neural signaling, immune-inflammatory responses, and neuroendocrine regulation. Furthermore, specific dietary interventions can modulate GM and associated metabolites to enhance cognitive function. Accordingly, this review summarizes dietary strategies, including probiotics and prebiotics, that may affect cognitive performance through the microbiota-gut-brain axis. Alterations in GM may potentially impact cognitive function. Metabolites, such as short-chain fatty acids, tryptophan metabolites, and lipopolysaccharides, act as critical mediators linking gut function and brain performance. Meanwhile, dietary components, including prebiotics, probiotics, and dietary fibers, can reshape gut microbial composition and function. It highlights the intestinal integrity and microbial homeostasis as potential targets for preventing and managing MCI.