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Oral Bacteria May Indicate Pancreatic Cancer Risk

TOP - Daily

Researchers have discovered a significant link between antibodies for multiple oral bacteria and the risk of pancreatic cancer.

The study, published in the journal Gut, found that high antibody levels for an infectious periodontal bacterium strain of Porphyromonas gingivalis were associated with double the risk for pancreatic cancer. Conversely, a 45% lower risk of pancreatic cancer was associated with high levels of antibodies for harmless “commensal” oral bacteria.

Although researchers have found previous connections between periodontal disease and pancreatic cancer, this study is the first to determine whether antibodies for oral bacteria are indicators of pancreatic cancer risk. It is also the first study to associate the immune response to commensal bacteria with lower pancreatic cancer risk. The physiological mechanism linking oral bacteria and pancreatic cancer remains unknown.

“This is not an established risk factor,” said Brown University epidemiologist Dominique Michaud, the paper’s corresponding author. “But I feel more confident that there is something going on. It’s something we need to understand better.”

To conduct the study, blood samples from over 800 Imperial College-led European Prospective Investigation into Cancer and Nutrition Study participants were used. The researchers selected 416 patients who did not develop pancreatic cancer and 405 patients who developed pancreatic cancer, but no other cancer.

Then, during their analysis of the blood, the researchers blinded themselves to which of the blood samples came from cancer patients and which did not. The analysis consisted of measuring antibody concentrations for 25 pathogenic and commensal oral bacteria. Researchers controlled for smoking, diabetes, body mass index, and other risk factors.

A noteworthy element of the study design was that the date of the blood samples preceded the diagnosis of pancreatic cancer by as much as a decade. In other words, the significant difference in antibody levels were likely not a result of cancer.

The researchers hypothesize that the relationship between high levels of antibodies for commensal bacteria and pancreatic cancer may indicate a natural and highly active immune response that is protective against cancer.

Source: Brown University.