What does GALT stand for and what is its role in the GI tract?

• A. Granulocyte-associated lymphoid tissue
• B. Gut-associated lymphoid tissue
• C. Gonadal-associated lymphoid tissue
• D. Gastrointestinal-associated lymphoid tissue

Answer: (B)

Gut-associated lymphoid tissue stands for GALT. It’s a key part of the mucosal immune system in the lining of the digestive tract. Within the gut, it includes organized structures like Peyer’s patches in the ileum and the appendix, plus scattered immune cells in the lamina propria. Its main job is to monitor what comes through the intestinal lumen and mount appropriate immune responses. Specialized cells called M cells bring antigens from the gut lumen to underlying immune cells, leading to activation of B and T cells and the production of secretory IgA to neutralize pathogens at the surface. At the same time, GALT helps maintain tolerance to harmless food antigens and the resident microbiota, preventing unnecessary inflammation. The other phrases don’t reflect the established term for this immune tissue.