Research advances in the correlation between oral microbiota and tumors

The oral microbiota plays a crucial role in multiple physiological processes, including protection against tissue damage, maintenance of mucosal barrier integrity, regulation of inflammatory responses, and preservation of both local and systemic immune homeostasis. Increasing evidence indicates that dysbiosis of the oral microbiota is closely associated with both oral malignancies, such as oral squamous cell carcinoma, and systemic cancers, including colorectal, liver, and pancreatic cancers, through interconnected pathways such as the oral–gut axis and the oral–gut–liver axis. Alterations in oral microbial composition have been implicated in tumor initiation, progression, and prognosis. Current research on the role of the oral microbiota in tumorigenesis remains at an early stage. Existing studies are largely observational and are limited by heterogeneity in study design, insufficient causal evidence in human cohorts, and challenges in standardizing oral microbiome sampling and analysis. Nevertheless, as an important modulator of tumor-related inflammation, immune regulation, and metabolic signaling, the oral microbiota provides a novel perspective for understanding cancer etiology. With continued technological advances and deeper mechanistic investigations, the oral microbiota is expected to emerge as a promising target for cancer prevention, early detection, precision therapy, and prognostic evaluation, offering new opportunities for translational oncology research and clinical practice.