Stem cells can secrete antimicrobial molecules to defend the stomach against bacteria, researchers have found.

Mucosal surfaces in the body — membranes that cover the surfaces of our internal organs — receive constant exposure to bacteria.

This is normal in most instances, as the rapid turnover of the mucosa means damaged cells are shed quickly. But damage to long-lived stem cells present in the mucosa can lead to the development of cancer.

The gastric stem cell pool is able to divide to generate new cells, but researchers at the Max Planck Institute in Berlin have discovered that they can also release antimicrobial molecules to fight against unwelcome bacteria.

In response to an infection, stem cells increase their turnover which can lead to hyperplasia, often a stage in the development of cancer.

But the team found that a subpopulation of stem cells in the very base of the gland does not respond with increased turnover.

“Instead, this population differentiates into secretory cells and begins to produce and release antimicrobial peptides into the gland—thus protecting their own niche from bacterial attack,” according to

Study investigators Michael Sigal and Thomas Meyer said the developments would have a huge impact on future studies.

“It would be of enormous clinical benefit if such antimicrobials could be used as markers to identify patients in whom this protective defense is compromised,” Sigal said.