Oral microbiome associated with differential ratios of Porphyromonas gingivalis and Streptococcus cristatus.

BACKGROUND

Periodontitis has been recently defined as a dysbiotic disease resulting from imbalanced oral microbiota. The transition of microbial communities from commensal to periodontitis-associated ones likely requires colonization by specific pathogens, including . We previously reported an antagonistic relationship between and and the role of in inhibition of the biofilm formation, invasion, and gingipain enzymatic activity of . Given the importance of as a keystone pathogen of polymicrobial communities, the determinants of levels, its interaction with the core microbiota, and association with the pathogenic potential of the microbial communities need to be addressed.

RESULTS

This present study intends to determine the role of in altering interactions of with other oral bacteria in a complex context. We collected dental plaque samples from periodontitis patients and assigned them into two groups based on their ratios of and . We then characterized microbial profiles of the dental plaque samples using shotgun metagenomic sequencing and subsequently compared oral microbial composition and functional capabilities between groups with high or low ratios. Taxonomic annotation showed significant differences in microbial compositions at both genus and species levels between the two groups. Notably, a higher microbial composition diversity was observed in the samples with low ratios. The antibiotic resistance gene profiles of the two groups are also distinct, with significantly increased diversity and abundance of antibiotic resistance genes in the dental plaque samples with low ratios, which likely lead to elevated virulence potential.

CONCLUSIONS

Overall, our work highlights the importance of ratios in influencing the virulence of the oral microbiome. Approaches to enhance ratios in oral microbial communities will be attractive for revising the dysbiotic oral microbiome.