Possible association between the microbiota in subgingival and atherosclerotic plaque in a cohort of patients with carotid stenosis

Background Periodontal pathogens have been implicated in systemic diseases, including atherosclerosis. This study investigates the relationship between subgingival and microbial colonization of carotid plaque in patients undergoing carotid endarterectomy (DRKS00021598).Methods Microbial samples from both subgingival and carotid plaques were collected from 25 hospitalized patients. Preoperative all patients underwent periodontal examination. The microbial composition was assessed using metagenomics sequencing of 16S rRNA gene (V3/V4 regions).Results Bacterial DNA was detected in both subgingival and carotid plaque samples. The microbial composition differed between both communities. Alpha diversity was significantly higher in subgingival samples than in carotid plaques (p = 0.039). Beta diversity analysis, (including unweighted UniFrac (p < 0.001), linear discriminant analysis, principal component analysis) confirmed significant differences between subgingival and carotid plaque microbiota. The study revealed overlaps in a few individual cases.Conclusions These findings show that carotid plaque microbiota differ from subgingival communities and are not exclusively of oral origin, suggesting additional systemic sources.