Tales from the crypts: Cells battle germs

Consider them the guardian angels of your small intestine.

Long known as Paneth cells, these sentries inhabit tiny pits in the intestine called crypts. Scientists now offer the best evidence yet that these cells defend other cells in the crypts by discharging bacteria-killing bursts of enzymes and other molecules.

Protecting the crypt’s so-called stem cells, which replenish the lining of the small intestine, is vital.