Oral Microbiome Interactions in Cancer Development

The oral cavity hosts a dynamic microbial community whose composition influences mucosal immunity, epithelial homeostasis and systemic health. Dysbiosis marked by proliferation of pathobionts such as Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella species initiates chronic inflammation, alters cytokine networks and generates genotoxic metabolites. These perturbations may promote epithelial cell proliferation, DNA damage and epigenetic reprogramming, thereby facilitating initiation and progression of oral and extra-oral malignancies. In addition to local effects, oral microbes can translocate to the nasopharynx, gastrointestinal tract and beyond, interacting with viral cofactors such as Epstein–Barr virus. Multi-omics analyses have revealed crosstalk between microbial metabolites and host signalling pathways—including E-cadherin/β-catenin, NF-κB and STAT3—that underpin tumour growth, invasion and immune evasion. Growing evidence supports the use of salivary or mucosal microbiome profiles as non-invasive biomarkers for early detection, risk stratification and monitoring of treatment response. Targeting microbial drivers through antimicrobial, probiotic or immunomodulatory strategies may offer novel avenues for prevention and adjunctive therapy in head and neck and gastrointestinal cancers.

Research from Nature Portfolio

A recent study uncovered aberrant migration of oral bacteria to the nasopharynx, identifying several species within tumour tissue that correlated with elevated Epstein–Barr virus load and local cytokine changes, thereby implicating microbial translocation in nasopharyngeal carcinoma risk. Foundational work profiling bacterial diversity in oral squamous cell carcinoma lesions demonstrated enrichment of periodontitis-associated taxa, notably Fusobacterium and Peptostreptococcus, accompanied by increased alpha diversity and distinct functional gene signatures. Parallel epidemiological research has described an “inflammatory bacteriome” dominated by Fusobacterium nucleatum and Pseudomonas aeruginosa in tumour biopsies, with predictive potential based on shifts in flagellar and lipopolysaccharide-related gene pathways.

Oral Microbiome Interactions in Cancer Development publication trend

The graph below shows the total number of articles in oral microbiome interactions in cancer development across all publications each year (not limited to Nature Index journals).

Technical terms

Dysbiosis: Disruption of the normal microbial balance, leading to overgrowth of pathogenic species.

Alpha diversity: Measure of species richness and evenness within a single microbial community sample.

CpG methylation: Addition of methyl groups to cytosine nucleotides in DNA at CpG sites, affecting gene expression.

Epithelial-mesenchymal transition (EMT): Process by which epithelial cells acquire migratory and invasive properties characteristic of mesenchymal cells.

Pathobiont: Opportunistic microorganism that can contribute to disease under certain conditions.

References

1. Role of Oral Microbiota in Cancer Development. Microorganisms (2019).
2. Microbes translocation from oral cavity to nasopharyngeal carcinoma in patients. Nature Communications (2024).
3. Inflammatory bacteriome featuring Fusobacterium nucleatum and Pseudomonas aeruginosa identified in association with oral squamous cell carcinoma. Scientific Reports (2017).
4. Bacteriome and mycobiome dysbiosis in oral mucosal dysplasia and oral cancer. Periodontology 2000 (2024).
5. Integrative analysis reveals associations between oral microbiota dysbiosis and host genetic and epigenetic aberrations in oral cavity squamous cell carcinoma. npj Biofilms and Microbiomes (2024).
6. Salivary microbiome profiles of oral cancer patients analyzed before and after treatment. Microbiome (2023).