Bacterial Community in Dental Biofilms Linked to Periodontal Disease: An Intra-subject Metagenomics Study

Abstract

Aims: To study the intra-subject subgingival plaque microbiota composition of gingivitis and periodontitis sites in periodontitis patients using 16s rRNA metagenomics. Methods: Samples of subgingival plaque were collected from 16 periodontitis participants enrolled on the study. The extracted DNA from dental plaque was sent to the Illumina laboratory for 16s rRNA metagenomics. The V₃ and V₄ region of 16s RNA gene were amplified and sequenced using Illumina technology. After quality filtering, 313480 sequences were obtained and arranged in OTU based on the 97% threshold. The reads were assigned to species. Results: The alpha diversity analyses revealed that periodontitis sites had more diverse and rich bacterial communities than gingivitis sites. However, the PCoA analysis (beta diversity) did not reveal any clustering of the bacterial community in gingivitis and periodontitis. Taxonomic analysis verified the presence of 56 known species. However, there was no apparent pattern in the bacterial community between gingivitis and periodontitis sites. Yet, a slight distinction was observed. Species like P. intermedia, R. dentocariosa and P. endodontalis were more abundant in gingivitis sites compared to periodontitis sites, while some other species like V. dispar, C. ochracea and A. segnis were more abundant in periodontitis sites. Conclusion: This study supports the fundamental idea that individual bacterial species are not responsible for the advancement of gingivitis to periodontitis but rather the abundance of bacteria in the bacterial community.

Keywords

• Intra-subject
• Periodontitis
• Gingivitis
• Subgingival plaque
• 16S RNA Metagenomics.