A specialized cell at the base of intestinal crypts that secretes antimicrobial peptides—your gut’s built-in defense system.Paneth cells are secretory epithelial cells located at the base of small intestinal crypts. They produce and secrete alpha-defensins (HD-5, HD-6), lysozyme, phospholipase A2, and REG3 lectins, maintaining antimicrobial defense at the crypt-villus interface. Paneth cell dysfunction is implicated in Crohn’s disease pathogenesis. Alpha-defensins from Paneth cells regulate intestinal microbiome composition and provide innate immune defense against enteric pathogens.