Exploring the Association between Oral Microbiome and Mild Cognitive Impairment: A Narrative Review

Objective: Some studies have investigated the association between oral microbiome and mild cognitive impairment (MCI). However, there needs to be more narrative reviews synthesizing this evidence. This study aimed to bridge this gap in the current knowledge. Methods: A comprehensive search was conducted on PubMed (MEDLINE) to identify studies examining the association between the oral microbiome and MCI. Search parameters and inclusion criteria were clearly defined, encompassing terms related to the oral microbiome, MCI, and their association. Two authors independently selected relevant studies and performed data extraction. Result: Four studies were included. Two cohort studies and two case-control reported an association between the oral microbiome and MCI. Conclusion: Based on the evidence synthesized from the included studies, the review suggests an association between MCI and the oral microbiome. Specifically, all included studies identified significant differences in the abundance of specific microbial species between individuals with MCI and those with normal cognitive function, underscoring the potential role of these species in neuroinflammatory diseases.