Bacteria from the mouth increase colorectal cancer mortality, according to researchers at Harvard. Their results were published in the journal Gut.
When F. nucleatum was present in colorectal cancer tissues, there was a significantly increased incidence of mortality from colorectal cancer. Greater quantities of the bacterium corresponded with shorter survival rates.
A significant factor in periodontal disease, F. nucleatum originates in the mouth but is commonly found throughout the digestive system. It has long been implicated in the pathogenesis of colorectal cancer, not only helping cancer cells grow but also blocking the immune system from attacking the cancer.
It has even been shown to cross the placental barrier and cause a term stillbirth in an otherwise healthy pregnancy.
The study authors concluded that the presence of F. nucleatum might be a good indicator of prognosis and a directive for future prevention and treatment strategies.
Similar research published earlier this year found that another periodontal pathogen, P. gingivalis, increases the risk of orodigestive cancer mortality.
Whether it is the presence of these bugs or the chronic, systemic inflammation that generally accompanies them, the research has made it clear that oral pathogens can bring significant harm to patients battling cancer—if not contributing to the development of cancer to begin with—even without the presence of clinical periodontal disease. What is often a silent, persistent infection can have grave impacts systemically and in the absence of traditional signs of periodontal disease.