In two separate studies, researchers found that Fusobacteria, associated with various human diseases, were hundreds of times more common in colorectal tumors than normal tissue.

Scientists in these two studies (one US and one Canadian) were surprised by the results as only about 15-percent of all cancers worldwide are known to be associated with infectuos agents (such as HPV with cervical cancer). The exact correlation is still unknown – are the bacteria present because they contributed to the cancer or because the cancer killed off all other bacteria normally fond in the intestinal tract?

The teams concluded that more research is needed before definitive conclusions can be drawn. Determining when the bacteria “arrive” in the colon could, if nothing else, allow for less invasive screening.