Integrative meta-analysis of the OSCC microbiome: from niche-specific heterogeneity to universal network and functional signatures

Background: While the association between oral squamous cell carcinoma (OSCC) and microbial dysbiosis is well-established, high inter-study heterogeneity has historically hindered the identification of universal biomarkers. Objective: To explore the profound influence of anatomical ecological niches on microbial profiles while identifying shared oncogenic signatures across diverse populations. Design: An integrative meta-analysis of independent OSCC microbiome cohorts was conducted. Results: as top driver of microbial community restructuring. Diagnostically, saliva-based models achieved superior accuracy compared to tissue and mucosal models, suggesting that saliva serves as an integrative reservoir for oral pathological changes. Functional profiling further revealed a significant functional convergence toward pathways essential for rapid bacterial proliferation and environmental adaptation, such as ribosome biogenesis, DNA replication, and flagellar assembly. Conclusions: These findings emphasize the necessity of standardizing sampling protocols and provide a robust scientific basis for non-invasive, saliva-based precision diagnostic strategies for OSCC.