M cells

M cells are specialized cells located in the lining of the small intestine, particularly in the Peyer’s patches. They play a key role in immune defense by sampling substances like bacteria, viruses, and other particles from the gut lumen. M cells transport these external agents across their surface into underlying immune tissues, where immune cells can recognize and respond to potential threats. This process helps the body detect pathogens early and orchestrate appropriate immune reactions. Thus, M cells are essential for gut immunity, acting as sentinels that monitor the intestinal environment and trigger immune responses when needed.