Oral Microbes Linked to Pancreatic Cancer Risk

Recent findings indicate that certain combinations of mouth microbes are connected to one of the most lethal types of cancer. This suggests that maintaining good oral hygiene might have benefits beyond simply keeping our teeth healthy.

According to Richard Hayes, a cancer epidemiologist from New York University, there’s increasing clarity that regular brushing and flossing may not just prevent gum disease but could also aid in reducing cancer risk.

The pancreas plays a vital role in our digestive system, producing enzymes and hormones necessary for nutrient absorption. Though pancreatic tumors are not common, those who do develop cancer often face a grim prognosis.

Hayes, alongside his colleague Yixuan Meng and their research team, analyzed health records and oral wash samples from over 300,000 individuals aged fifty to seventy.

In their research, they found that 27 microbes present in mouth samples were associated with more than three times the risk of pancreatic cancer. In the U.S., this disease affects approximately 1 in 56 men and about 1 in 60 women during their lifetime.

The research suggests that some oral microbes may reach the pancreas by traveling through saliva into the digestive tract. The researchers specifically identified three types of bacteria — Porphyromonas gingivalis, Eubacterium nodatum, and Parvimonas micra — as well as a common fungus, Candida tropicalis, linked to a higher likelihood of being diagnosed with pancreatic cancer.

However, Hayes notes that this doesn’t confirm that these microbes directly cause cancer. Instead, the observed patterns indicate species that need further study. Interestingly, other strains of Candida and bacteria were shown to be associated with a reduced risk, suggesting that the specific composition of oral microbes is crucial for overall health.

The data for this study was drawn from two long-term health studies in the U.S., namely the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and the American Cancer Society’s Cancer Prevention Study-II Nutrition Cohort.

Out of the participants, 445 developed pancreatic cancer, and their data was compared to 445 healthy individuals.

The research found eight oral bacteria linked to decreased cancer risk and 13 that were associated with an increased risk, as noted in their published work.

The survival rate for pancreatic cancer remains low — about 13 percent over five years — largely due to late diagnoses. Symptoms often only become apparent when the disease is in an advanced stage. Recognizing early risk factors, like the makeup of oral microbiomes, could facilitate earlier detection.

By profiling bacteria and fungi in the mouth, oncologists might better identify individuals in need of pancreatic cancer screenings, according to Jiyoung Ahn from NYU.

The team is planning to explore how viruses might also influence these risks in future studies.

This research has been published in JAMA.