Oral Bacterial and Fungal Microbiome and Subsequent Risk for Pancreatic Cancer

Pancreatic cancer is one of the most lethal malignancies worldwide, with five-year survival rates below 15%. Its diagnosis is often delayed, which severely limits the chances of curative treatment. Traditionally, risk factors such as smoking, obesity, chronic pancreatitis, and certain genetic syndromes have been recognized, but these account for less than 30% of cases. Therefore, it is essential to explore other biological determinants that may contribute to its development.

The study by Meng and colleagues, published in JAMA Oncology in 2025, provides novel evidence on the role of the oral microbiome in the development of pancreatic cancer. Analyzing data from more than 122,000 participants across two large U.S. cohorts, the authors found that the presence of certain periodontal bacteria, such as Porphyromonas gingivalis, Eubacterium nodatum, and Parvimonas micra, as well as the abundance of fungi from the Candida genus, was significantly associated with an increased risk of this disease. Conversely, other bacterial species appeared to exert a protective effect, suggesting that microbial balance in the oral cavity may modulate carcinogenic processes at a distance.

A particularly relevant finding was the development of a Microbial Risk Score (MRS), based on the combination of 27 bacterial and fungal species. This index showed that a one–standard deviation increase in the MRS was associated with more than a threefold higher risk of developing pancreatic cancer. This marker represents a potentially useful tool for risk stratification and the implementation of preventive strategies targeted at vulnerable populations.

This work carries significant clinical and public health implications. First, it reinforces the connection between oral health and serious systemic diseases, underscoring the importance of prevention and timely treatment of periodontal disease. Second, it opens the door to the possibility of using noninvasive, oral-based tests to identify individuals at higher risk of pancreatic cancer, thereby facilitating earlier preventive interventions.

In Costa Rica, pancreatic cancer holds a prominent place in cancer mortality, also characterized by late diagnoses and limited therapeutic options. The research presented is particularly applicable in our setting for several reasons. First, it underscores the need to strengthen oral health as an integral component of cancer prevention policies, in a country where access to preventive dentistry is not always equitable. Second, it highlights the importance of promoting local research on the microbiome in the Costa Rican population, which would allow these findings to be validated and adapted to our genetic, dietary, and epidemiological realities. Finally, it presents the opportunity to integrate oral health into oncological screening programs and personalized medicine strategies, helping to reduce the burden of a disease that, until now, has been virtually untreatable when detected at advanced stages.

Meng Y, Wu F, Kwak S, Wang C, Usyk M, Freedman ND, Huang WY, Um CY, Gonda TA, Oberstein PE, Li H, Hayes RB, Ahn J. Oral Bacterial and Fungal Microbiome and Subsequent Risk for Pancreatic Cancer. JAMA Oncol. 2025 Sep 18:e253377. doi: 10.1001/jamaoncol.2025.3377. Epub ahead of print. PMID: 40965868; PMCID: PMC12447289.