Characterisation of the human oral microbiome in patients with coronary artery disease using next-generation sequencing of 16SrRNA amplicons

Introduction: Oral health is suspected to be linked to heart disease since species of bacteria that cause periodontitis and dental caries have been found in the atherosclerotic plaque in arteries in the heart. Objectives: The aim of this study was to characterize the oral microbiome in patients with coronary artery disease (CAD) and in a patient with dental caries (DC) without any clinical symptoms of CAD. Methods: DNA was extracted from the oral swabs collected from the patients and sequencing was performed by next generation sequencing method using Illumina (MiSeq) platform. The resulting sequencing data set was analysed using QIIME. Results: A total of 31 phyla were found in all the samples. The predominant phylum found in both CAD and DC was Firmicutes (46.09% & 38.98%), Proteobacteria (17.73% & 9.79%), Fusobacteria (13.44% & 17.95%), Bacteroidetes (11.82% & 22.73%), Actinobacteria (8.33% & 7.71%) and TM7 (2.25% & 2.71%). We found a similarity in the bacterial diversity in the two groups of patients. Conclusion: A comparison of the oral microbiome in patients with CAD and DC shows a similarity in the composition of the oral microbiota with variations in the proportion of a few genera.