In 2011, investigators discovered that a bacteria known as Fusobacteria, is often found in colon cancer tissue. Even though the bacteria may be an innocent bystander, it might also be a causative agent for colon cancer, much the same way as Helicobacteria pylori can be for gastric carcinoma.

In a new multicenter study, researchers pooled over 500 cases of colorectal cancer and confirmed that fusobacterial DNA was found in nearly 50% of primary tumors. They also found that this bacteria and it’s proteins were primarily in malignant cells rather than in non-malignant cells. This bacteria was cultured from primary and metastatic tumors.

Also, human colon cancer cells that were positive for fusobacterial DNA often grew into tumors when implanted in mice. When cells from those tumors were transplanted into other mice, they retained their bacterial DNA and grew into new tumors. When mice with tumors containing fusobacteria DNA were treated with metronidazole, an antibiotic to which fusobacteria are sensitive, tumor growth decreased. This did not occur with other antibiotics to which the bacteria was not sensitive.

This study suggests that such tumors might be prevented and treated by antimicrobial agents. More studies are needed, but this and more studies may lead to breakthroughs in cancer treatments.

Bullman S et al. Analysis of Fusobacterium persistence and antibiotic response in colorectal cancer. Science 2017 Dec. 15; 358:1443.