Periodontal Disease and Its Association with Porphyromonas gingivalis: Current Understanding of Microbial Dysbiosis, Immunopathology and Immune Evasion

Porphyromonas gingivalis is described as a keystone pathogen associated with periodontal disease (PD), which exhibits enhanced representation upon microbial dysbiosis in such a chronic inflammatory disease. This oral pathogen drives and contributes to a dysregulated immune response, resulting in stages of aggressive destructive immune activation and inflammation punctuated by immune suppression, which underlies the relapsing–remitting nature of this disease. The understanding of key mechanisms and balance between protective innate, adaptive immune responses and dysregulated responses, linked to changes in the oral mucosal microbial environment, will afford researchers the potential to manipulate oral mucosal environments for clinical benefit. This review focuses on the dynamic interactions between the oral pathogen P. gingivalis and the immune system with an emphasis on immune evasion and how the potential correction of these mechanisms may benefit future therapeutic interventions, leading to the successful treatment of PD.