The Role of Fusobacterium in Periodontal Disease and Its Implications for Cardiovascular Health

<i>Fusobacterium</i> species, particularly <i>Fusobacterium nucleatum</i>, is known as a key adhesive bridging microorganism in the development of periodontal disease, inducing microbial imbalances and chronic inflammation within the oral cavity. Their role is to provide a bridge between both early colonisers (such as Streptococcus and Actinomyces) and late colonisers (such as <i>Porphyromonas gingivalis</i> and <i>Treponema denticola</i>), which results in multispecies biofilm formation. This triggers an immune reaction which may provide both a protective and destructive effect on the periodontal ligament and alveolar bone. Recent studies have discovered their significance beyond oral pathology. Therefore, <i>Fusobacterium</i> have been implicated in several systemic diseases, including cardiovascular disease (CVD). Virulent mechanisms, such as adhesion, invasion, modulation of host immunity, and pro-inflammatory signalling, contributes to periodontal tissue bone loss and entry into the circulation. Circulating bacteria interact with vascular endothelium and promote atherosclerotic plaque formation. The role of <i>Fusobacterium nucleatum</i> as a microbial link between periodontal disease and cardiovascular disease is highlighted and discussed. Overall, current evidence is mostly observational and preclinical, supporting an associative link between <i>F. nucleatum</i>-mediated periodontal disease and CVD. The literature highlights key mechanistic pathways while underscoring the important need for longitudinal studies to clarify causality and identify target therapeutic interventions.