Multimodal Interventions Targeting Gut Microbiota and Microbial Metabolites in Cognitive Impairment

Mild cognitive impairment (MCI) is a transitional stage between normal aging and Alzheimer's disease (AD). Recent studies suggest that alterations in gut microbiota and microbial metabolites are associated with cognitive decline, highlighting the gut-brain axis as a potential therapeutic target. This narrative review explores current evidence on the relationship between gut microbiota, microbial metabolites, and MCI. It summarizes intervention strategies including probiotics, prebiotics, synbiotic, fecal microbiota transplantation, dietary modifications, medicinal herbs, phytochemicals, metformin, and lifestyle factors. Probiotic strains such as Lactobacillus and Bifidobacterium have shown cognitive benefits. Adherence to the Mediterranean and MIND diets, as well as metformin use, is associated with lower MCI risk. Novel strategies, including plant-based compounds and nature exposure, show promise in modulating gut microbiota and improving cognitive outcomes. Gut microbiota modulation represents a promising avenue for early intervention in MCI. Personalized, multifactorial approaches based on individual microbiome profiles may enhance prevention and management strategies. However, more high-quality clinical trials are needed to establish evidence-based guidelines.