Recent research published in Nature suggests a link between a type of bacteria known for causing dental plaque and a form of resistant colorectal cancer. Found in half of the tested tumors, this bacterium may protect cancer cells from treatment drugs, opening potential avenues for new treatment and screening methods.
Colon cancer is a major cause of cancer deaths in the U.S., with rising rates among younger people. Many of these cases are diagnosed at more advanced, aggressive stages. The reason for this increase, particularly in younger individuals, remains unclear, with the new study not directly addressing this age-related trend.
The bacteria in question, Fusobacterium nucleatum, has been suspected for nearly a decade to contribute to colorectal cancer growth. Typically found in the mouth and associated with gum disease, it was unclear how this bacterium could survive the journey to the colon and affect tumor cells. The study involved examining the bacterial composition of colorectal tumors and stool samples from over a thousand individuals, half of whom had no cancer.
Researchers discovered two subspecies of the bacteria, with one type acting as a protective shield for tumors against cancer-fighting drugs. This particular subspecies was present in 50% of the colorectal tumors and was associated with a poorer prognosis, reduced chemotherapy response, and increased recurrence risk.
The study also explored how Fusobacterium nucleatum might travel to the colon, surviving stomach acid. This finding has significant implications for targeted therapies, with potential new treatment strategies involving antibiotics to enhance chemotherapy effectiveness.
Future preventative measures could include identifying the bacteria in the mouth and administering antibiotics early or using its presence as a marker for increased colon cancer risk. Researchers also contemplate the possibility of using the bacteria for direct cancer treatment by genetically modifying it to carry drugs into tumors.
This research highlights the growing understanding of the microbiome’s role in cancer risk and the emerging importance of this concept in cancer research.