<i>Helicobacter pylori</i> in oral and gastric pathologies: a narrative review of potential bidirectional pathogenic interactions

The association between periodontal diseases and gastrointestinal conditions, particularly those associated with Helicobacter pylori and systemic inflammation, has garnered increased scientific attention because of its clinical and public health implications. These diseases, which affect both the oral cavity and the digestive system, have shared pathophysiological mechanisms that link inflammatory processes and bacterial transmission pathways. The possible presence of H. pylori in the oral cavity has sparked interest regarding its potential colonization of periodontal tissues and acting as an extragastric reservoir. This narrative review describes H. pylori’s possible survival mechanisms in this oral microenvironment and its clinical significance in the interaction between oral and gastric conditions. We propose that periodontitis might promote gastric H. pylori infection by stimulating systemic inflammation, and oral colonization might serve as a reservoir for gastric reinfection. Future studies may involve advanced technologies such as metagenomics and proteomics. The eradication of H. pylori in the oral cavity may provide a strategy to prevent gastric reinfection. The findings described herein highlight the importance of this bacterium in two different pathologies sharing a close anatomical relationship.