Salivary Microvesicle Methylome and Microbiome Profiles in Periodontitis: An Exploratory Study

Salivary microvesicles (MVs) are nanosized extracellular vesicles from the host and microbiota whose cargo may mirror the biological state of their parent cells. This cross-sectional study aimed to explore the diagnostic power of host methylome and microbiome profiles of MVs in various periodontal disease states.

This exploratory study recruited 20 healthy, 16 gingivitis and 26 stage III/IV periodontitis cases. The origins of salivary host-MVs were identified using a multiplex extracellular vesicle (EV) kit. The microbiome and host methylome profiles of MV DNA were analysed using 16S rRNA sequencing and methylated DNA immunoprecipitation sequencing (MeDIP-seq), respectively.

The periodontitis group showed increased CD63+, CD45+, CD29⁺ and CD24⁺ MV subpopulations (AUC > 0.7), along with significantly higher bacterial outer membrane vesicles (AUC > 0.89) from Treponema, Fretibacterium and Treponema denticola, compared to both healthy and gingivitis groups, as well as the non-periodontitis (combining healthy and gingivitis) group. MeDIP-seq identified 1196 differentially methylated regions across 3' UTRs, CDS, introns and intergenic regions (AUC > 0.9), distinguishing periodontitis from the other groups. These methylated genes were enriched in inflammation-related pathways, including AMP-activated protein kinase (AMPK) and Toll-like receptor 4 (TLR4) pathways.

This exploratory study found that host methylome and microbiome profiles in salivary MVs reflect periodontal disease status, and hence supports their potential as non-invasive liquid biopsy biomarkers for periodontitis.