Effects of Periodontal Pathogens Porphyromonas gingivalis and Aggregatibacter actinomucetemcomitans on Modeling Subgingival Microbiome and Impairment of Oral Epithelial Barrier.

Periodontitis is an exemplar of dysbiosis associated with the coordinated action of multiple members within the microbial consortium. The Polymicrobial Synergy and Dysbiosis hypothesis proposes a dynamic host-microbiome balance, with certain modulators capable of disrupting eubiosis and driving shifts towards dysbiosis within community. However, these factors remain to be explored. We established a Porphyromonas gingivalis (P. gingivalis)- or Aggregatibacter actinomucetemcomitans (A. actinomucetemcomitans)-modified subgingival microbiome model and 16S rRNA sequencing revealed that P. gingivalis and A. actinomucetemcomitans altered the microbiome structure and composition indicated by α and β diversity metrics. P. gingivalis increased subgingival dysbiosis index (SDI), while A. actinomucetemcomitans resulted in a lower SDI. Furthermore, P. gingivalis-stimulated microbiomes compromised epithelium function and reduced expression of tight junction proteins, whereas A. actinomucetemcomitans yielded mild effects. In conclusion, by inoculating P. gingivalis, we created dysbiotic microcosm biofilms in vitro resembling periodontitis-related subgingival microbiota, exhibiting enhanced dysbiosis and impaired epithelium integrity.