Figure 2. P. gingivalis exploits complement and causes dysbiotic inflammation.

P. gingivalis subverts complement and impairs host defense leading to altered composition and increased numbers of periodontal commensal bacteria which, in turn, cause complement-dependent periodontal inflammation and bone loss. The inflammatory environment is favorable to further bacterial growth as it provides the dysbiotic microbiota with a nutrient-rich gingival inflammatory exudate. Numbers indicate a possible sequence of events, although the overall process represents a self-feeding cycle that drives and sustains persistent inflammation.