Background: An improved comprehension of the oral microbiota function in the pathogenesis
of disease will contribute to the diagnosis and treatment of both hypertension and periodontal
disease. In our study, a comparison of the salivary microbiome between hypertension and
Non-hypertension cohorts was designed to reveal microbial signatures.
Methods: Patients were divided into four sub-groups: Gingivitis, and Periodontitis (stage 2, 3, and
4). Then, hypertension and non-hypertension cohorts were split into periodontal health and periodontitis
subgroups. The salivary samples were processed for DNA extraction (n=246). The V3-V4
hypervariable regions of microbiome 16S rRNA genes were amplified. Finally, sequencing libraries
were constructed and subjected to bioinformatics and statistical analyses.
Results: The oral microbial diversity decreased in both hypertension and periodontal disease
groups compared to the healthy ones. At the genus level, the diversity showed 100 different operational
taxonomic units (OTUs) for differential abundance testing. The first trend showed OTUs decreased
in relative abundance with increasing periodontal disease, as well as hypertension and nonhypertensive
groups. For this trend, OTUs comprise of a mix of primarily anaerobic commensals
and potential acute diarrhea pathogens. The second trend was that the diversity of genera was decreased
in the hypertension group relative to the non-hypertension group, including other anaerobic
bacteria related to periodontal disease.
Conclusion: Microbiota diversity decreased in the hypertension group and different stages of
periodontal disease groups. However, Neisseria and Solobacterium genera increased in the coexisting
hypertension and periodontal disease group. Certainly, these findings indicate that the
abundance of genera continues to change due to additional stresses caused by co-existing conditions.