Abstract: Objective: To study the composition and function of the oral microbial flora of patients with periodontitis by metagenomic method combined with high-throughput sequencing technology, and explore the correlation between the composition and function of microorganisms and the occurrence and development of periodontitis. Methods: Saliva and subgingival plaque samples of 10 patients with periodontitis were collected, and total microbial DNA was extracted from each sample to build the macro-genome library, and MGISeq-2000 sequencing was conducted, while bioinformatics analysis was conducted using Metaphlan2 software and Humann2 software respectively. Results: Among the 20 samples, the microbial composition analysis results showed that at the genus level, the average relative abundance of Porphyromonas in the saliva and subgingival sample groups was not statistically different (P>0.05); the relative abundance of the Prevotella and Capnophagocytes were statistically different between the two sample groups (P<0.05). At the species level, the relative abundance difference of Haemophilus parainfluenzae and Neisseria flavus between the two sample groups was statistically significant (P<0.05). The result of functional analysis showed that the relative abundance of the two groups of contributing bacteria and sequences was statistically different (P<0.05). Conclusions: The results suggested that the subgingival microbe samples may be more representative for the study of periodontitis pathogenic bacteria and that the use of metagenomics to study metabolic pathways related to periodontitis disease may deserve further study.

Key words:

periodentitis, ?metagenomics, ?high-throughput sequencing technology, ?oral microbiome