Examining the body's microbiome composition is a relatively new field in medical science, said Dr. Jiyoung Ahn, an Associate Professor of Epidemiology at New York University School of Medicine. Research from the past five years found that 80 percent of bacteria residing in the human body cannot be cultured in a lab dish. While certain factors such as smoking and alcohol may spur changes in the oral microbiome, it is still hoped that changes in the mouth's bacteria may one day play a role in cancer diagnosis and potential treatments, Dr. Ahn added. (Related: Know more about potential cancer treatments at CancerSolutions.news)
Researchers at the University of Buffalo in New York found that gum disease-causing bacteria may cause the onset of breast cancer. An analysis of 73,000 postmenopausal women revealed that women who had the gum disease had a 14 percent higher risk of developing breast cancer. Data also showed that among women who quit smoking with the past two decades, those with the gum disease had a 63 percent increased risk of breast cancer. According to the scientists, oral bacteria may enter the circulatory system, which then negatively affects breast tissues.
A 2011 study also found a connection between oral bacteria and breast cancer onset. Researchers examined more than 3,000 women aged 30 to 40 years. Study data showed that women who had chronic gum disease or had lost teeth due to periodontal disease were more than twice as likely to develop breast cancer compared with women who had healthier gums. The findings were published in the Journal of Pharmacy & BioAllied Sciences.
Another study showed that poor oral health may increase the risk of developing pancreatic cancer. Research presented at the annual meeting of the American Association for Cancer Research revealed that people with higher levels of the oral bacteria P. gingivalis had up to 60 percent increased odds of pancreatic cancer than those with lower levels. Data also showed that the oral bacteria A. actinomycetemcomitans was also associated with an increased risk of pancreatic cancer.
A study published in the journal Clinical Cancer Research revealed that the oral bacteria F. nucleatum played a role in esophageal cancer development. Researchers at the Kumamoto University in Japan examined DNA in cancer tissue samples of 325 patients and found that patients who tested positive for the oral bacteria had shorter survival times than those who tested negative for the bacteria.
“This study suggested that the oral cavity bacterium F. nucleatum may be involved in the development and progression of esophageal cancer via chemokines. It should be noted that it is still unknown whether F. nucleatum itself causes esophageal cancer. Further analysis by more institutions, preferably world-wide, is desired since intestinal flora differs between individuals. In future research, after elucidating the role of F. nucleatum in esophageal cancer development in more detail, we should be able to develop new drugs to better treat this form of cancer,” said Professor Hideo Baba, the study's lead researcher.
A 2016 study also found that an oral bacteria called fusobacterium increased the risk of bowel cancer. The bacteria was known to induce bleeding gums, and was found to be more common in cancerous tumors that normal cells.