Study on the association and potential mechanisms between oral microbiota and post-stroke cognitive impairment
Objective Investigate the oral health and oral microbiota characteristics in patients with post-stroke cognitive impairment (PSCI), explore the predictive value of characteristic microbial species for early cognitive impairment, and reveal the potential association mechanism of oral microflora with PSCI.Methods This study enrolled patients with PSCI and post-stroke non-cognitive impairment (PSNCI). Clinical data were collected from all participants, and subgingival plaque samples were harvested for 16S rDNA gene sequencing. We explored the relationship between patients' oral health status and cognitive function; comparative analysis the composition and diversity of oral microflora between the two groups; identified differential genera using LEfSe analysis, constructed a random forest prediction model, and assessed the predictive value of characteristic oral genera for PSCI with ROC curves; performed correlation analysis to evaluate the association between oral microflora and clinical characteristics; and performed functional prediction based on the KEGG database using PICRUSt2 software.Results Patients in the PSCI group had significantly poorer oral health status (P=0.003), and the diversity and abundance of their oral microflora were significantly lower than those in the PSNCI group (P<0.05). LEfSe analysis revealed significantly higher Streptococcus abundance in the PSCI group (P=0.007) and significantly higher Leptotrichia abundance in the PSNCI group (P=0.006). The prediction model indicated that Streptococcus, Leptotrichia, and Campylobacter had high predictive value for PSCI, with an area under the curve (AUC) of 91.67%. Correlation analysis results showed that Streptococcus was significantly negatively correlated with cognitive function scores, Leptotrichia was significantly positively correlated with cognitive function scores, and Leptotrichia was significantly negatively correlated with oral health scores and the occurrence of periodontitis (P<0.01). Functional prediction analysis revealed that the gene abundances of PSCI group in the functional pathways of amino acid metabolism, genetic information defense, protein translation and processing, and nucleotide synthesis were significantly higher than PSNCI group (P<0.05).Conclusions Significant differences were observed between the PSCI and PSNCI groups in oral health status, oral microbiota composition, and predicted microbial functions. Streptococcus and Leptotrichia were identified as characteristic genera distinguishing the two groups. These findings offer novel perspectives for the early diagnosis and therapeutic management of PSCI.