Does colibactin cause APC gene mutations in colorectal cancer?

We analyzed the available evidence and found that in colorectal cancers infected with bacteria producing colibactin, this toxin is linked to a specific pattern of DNA damage that appears in about one-quarter of harmful mutations in the APC gene [1]. The APC gene plays a key role in controlling cell growth, and when it’s damaged, it can contribute to the early stages of tumor formation. What we’ve found so far is that colibactin’s signature damage matches up with these mutations in a consistent way across the studies reviewed. There are no studies in our analysis that contradict this link. The evidence we’ve reviewed leans toward colibactin playing a measurable role in shaping these particular genetic changes. However, we cannot say this is the only way APC mutations occur, or that colibactin always leads to cancer. The data shows a pattern, not a guaranteed cause. This suggests that if someone has colorectal cancer and their tumor carries this specific DNA damage pattern, it may be worth considering whether colibactin-producing bacteria were involved. But many other factors — like diet, genetics, and lifestyle — also influence cancer development. For now, this connection remains one piece of a much larger puzzle.