According to a new study in the journal Nature, E. coli infections may be linked to bowel cancer. Some species of the intestinal microbiota, which is the collection of bacteria and viruses that live in the human gut, have been associated with colorectal cancer, but a direct role hasn’t been proven.
As it turns out, E. coli bacteria carry what is called a pathogenicity island pks, that creates enzymes that synthesize a compound called colibactin. Colibactin causes double-strand breaks in cultured cells. This damage can lead to cancer over time. Colibactin is found more often in fecal samples of people who do have bowel cancer than healthy people.
Scientists don’t know how many cases of bowel cancer may be linked to the E. coli bacteria, but estimate that as many as 5% of these cases may be linked to this pathogen. The strain of E. coli that causes this damage is not one that causes food poisoning outbreaks. So people who have had E. coli food poisoning infections don’t need to worry.
In the study, scientists grew miniature replicas of the human gut to test how this toxin damages cells. Then, they compared the damage with actual bowel cancer samples. They found identical patterns of DNA damage in 5% of the samples. This is the first time that bacterial toxins and genetic damage that can cause cancer have been linked.
Researcher Professor Hans Clevers from the Hubrecht Institute in The Netherlands told the BBC that “Common antibiotics will kill these bacteira. This is the first time we have seen such a distinctive pattern of DNA damage in bowel cancer, which has been caused by a bacterium that lives in our gut.”
Doctors could help patients prevent bowel cancer by using antibiotics to get rid of the pathogen before it can cause damage. And this information may help researchers develop a more sensitive test for detecting bowel cancer and people who are more at risk for developing this illness.
