Mouth-heart axis: contribution of oral dysbiotic bacteria in the initiation and development of cardiovascular conditions

The oral microbiota begins to establish at birth and develops over time under the influence of genetic factors, environmental exposures, diet, and individual oral health behaviors. In a healthy state, these microorganisms exist in a balanced ecosystem; however, disruption of this balance, known as oral dysbiosis, can promote oral diseases such as dental caries and periodontitis (PD). Growing scientific evidence indicates that the impact of oral microbial imbalance may extend beyond the oral cavity. With advances in molecular detection techniques, oral bacterial species have been identified in distant body sites, including heart valves, suggesting a possible association between oral dysbiosis and cardiovascular disease. Chronic periodontal inflammation and microbial imbalance may allow bacteria or their inflammatory products to enter the bloodstream, leading to bacteremia via direct invasion or immune-mediated mechanisms. These processes may contribute to systemic inflammation and potentially influence the development and progression of cardiovascular disease. This study aims to review and summarize current evidence on the relationship between oral dysbiosis and cardiovascular disease, with particular focus on the mechanisms by which chronic oral inflammation and microbial imbalance may contribute to bacteremia and systemic inflammatory pathways that influence cardiovascular health.