A team of scientists at the University of Edinburgh are reporting on the possibility of a connection between a strain of E. coli and colon cancer. The implicated bacteria is enteropathogenic E. coli or EPEC. EPEC is a group of bacteria that cause gastroenteritis in humans, but lacks the shiga-toxins associated with shiga toxin producing E. coli (STEC). The STEC family includes the notorious E. coli O157:H7 strain.
According to the report, the study showed a "strong" suggestion that the bacteria is able to hamper the body’s fight against bowel cancer. According to the study, the bacteria significantly reduced the levels of two key proteins needed to repair damage to DNA. The Press Association report explains:
"The EPEC bacteria achieved this by attaching to the colon cells and inserting proteins into them which appeared to inactivate the cells’ repair system. It is known that a breakdown of this system puts the colon cells at greater risk of becoming cancerous."
Lead author of the study Dr Oliver Maddocks said: "We can’t say for certain that this type of E.coli bacteria definitely cause colon cancer, as it is possible these patients acquired the bug after their tumors developed. But our laboratory work does strongly suggest that the bacteria are able to influence colon cells in a way that might predispose them to cancer, and so there is a real chance that infection could aid the development of colon tumors."