Scientists at Johns Hopkins have found how a poison from gut bacteria starts its attack on the bowel. The bacteria are called Bacteroides fragilis. They live in the gut of up to 20% of healthy people. Having these bacteria does not mean a person will get cancer.
Some types of these bacteria make a poison called BFT. It can damage the bowel's inner layer and help cancers grow. Scientists found that BFT first attaches to claudin-4. This is a protein, a material in cells that helps keep them close together.
The team turned off genes in bowel cells to study the poison. Genes carry instructions for cells. Without the gene for claudin-4, the poison could not attach. It also could not damage another protein that helps hold cells together.
The scientists then made a protein with parts of claudin-4 to act as a trap. The poison attached to this trap instead of the bowel cells. This protected mice from damage, but it does not show that the trap prevents bowel cancer. Scientists still need to test whether this approach is safe and works in people.
