While scientists already knew that the intestinal microbiome is both beneficial and harmful to human health, a new study revealed that a toxin released by gut bacteria might cause bowel cancer.
More specifically, recent research revealed that patients with bowel cancer present higher levels of some specific strains of Escherichia coli. Besides, the study showed that a toxin released by E.Coli is modifying the DNA in the gut cells which might become cancerous tumors.
“While some strains of E. coli can cause food poisoning, others are more friendly and form part of the bacterial community in a healthy gut. Previous studies have found about 20 percent of E. coli strains produce a DNA-damaging toxin called colibactin. People with inflammatory bowel disease and bowel cancers often have elevated levels of these strains in their digestive systems,” NewScientist reported.
Toxin Released By Gut Bacteria Might Cause Bowel Cancer
In the new study, Emily Balskus at Harvard University in Massachusetts and her co-workers focused on which colibactin is the culprit in the E.Coli infestation in the human gut. To see that, they injected colibactin-producing E. coli into human gut cells.
The researchers noticed that the toxin delivered by Escherichia coli in the intestines is damaging the DNA of gut cells, severely. On the other hand, tests involving non-colibactin-producing E.Coli did not show the same outcomes. When the scientists repeated the experiment using mice cells, the team observed the same results.
“It’s the first time we see evidence that colibactin directly damages DNA in cells and mice,” explained Balskus from Harvard University in Massachusetts, and the study’s leading author.
The toxin released by gut bacteria causes modifications in the DNA within 16 minutes after the microorganisms release it. The researchers admitted that further studies would be needed to assess if gut bacteria is indeed behind bowel cancer, “but in other settings, such as tobacco products, there is good evidence that DNA destruction is carcinogenic,” concluded Balskus.