Salivary Microbiome and Periodontal Health in Myocardial Infarction Patients
Objectives: Previous studies have shown that patients with periodontal disease have a higher risk of cardiovascular disease. However, the mechanism behind the association is not known. The purpose of this study was to characterize and compare the salivary microbiome between myocardial infarction (MI) and periodontal disease.
Methods: Medical review and dental examinations with saliva samples were obtained from 1,214 subjects with (449) and without (765) recent MI. The V3-V4 region of 16S rRNA gene was amplified and sequenced on Illumina MiSeq platform. Sequencing analysis was performed against the Human Oral Microbiome Database (HOMD) with 97% similarity aimed at species level. Alpha diversity was accessed by observed OTUs and Chao1 metrics. The differences between MI cases and controls were determined using Mann–Whitney U test. Logistic regression was employed to control for confounding effects.
Results: There was an association between MI and periodontal status (χ2=7.2E-16; p<0.05). In both MI case and control group, alpha diversity was higher as periodontal disease severity increased. The alpha diversity was significantly higher in MI controls of periodontal healthy/mild and moderate groups, while it was not in periodontal severe group. When we focused on red and orange complex, Treponema denticola, Streptococcus constellatus, Prevotella nigrescens, Parvimonas micra, Fusobacterium nucleatum animalis, Fusobacterium nucleatum nucleatum and Campylobacter gracilis showed significantly different abundance between MI cases and controls. After considering confounding factors, differences of these bacteria remained significant. In MI cases, T. denticola, S. constellatus and P. micra were in higher abundance, but other species were less abundant.
Conclusions: We found a significant correlation between MI and periodontal disease. Our results show that the salivary microbiome differed significantly between MI cases and controls. These bacteria may play a role in MI progression; further investigation of the mechanism of this association could be useful for prevention of and better management of MI and periodontal disease.