Multi-omics profiling reveals key microbial and metabolic variations in ischemic stroke: insights into gut and oral microbiota

Dysbiosis of oral and gut microbiota may influence ischemic stroke (IS) pathogenesis through immune and metabolic mechanisms. This study investigated microbial translocation between oral and gut niches and its functional metabolic impact in IS patients. A total of 57 individuals were analyzed, including 25 controls (FC/KC) and 32 IS patients (FS/KS). Samples were obtained from the gut and oral subgingival plaque. The microbiome analysis was performed using the PacBio platform 16 S rRNA full-length gene sequencing, while non-targeted metabolomics was used to assess intestinal metabolites. The oral cavity of IS patients harbored abundant periodontal pathogens, including Porphyromonas and Fusobacterium. Bacterial genera (such as Streptococcus, Neisseria, Ligilactobacillus, Leptotrichia, Blautia, Veillonella, and Capnocytophaga) significantly overlapped between the oral and gut niches in IS patients, suggesting mutual transfer. IS patients exhibited increased diversity and dysbiosis in their gut microbiota, characterized by a deficiency of short-chain fatty acids (SCFA)-producing bacteria (Bacteroides and Faecalibacterium), and an enrichment of opportunistic pathogens (Streptococcus and Ligilactobacillus). Metabolomic analysis revealed concomitant disturbances in microbial metabolism, marked by decreased SCFAs (butyrate) and increased levels of specific amino acids (L-tryptophan). These metabolic changes were correlated with the microbial shifts. IS is associated with distinct dysbiosis in both the oral and gut ecosystems, which are interconnected through bacterial translocation. The metabolic disruption may link microbial dysbiosis to stroke pathogenesis through the oral-gut axis.