AHR and colitis: In a murine model of dextran sulfate sodium (DSS)-induced colitis, administration of a Trp-deficient diet or depletion of AhR encoding genes exacerbated colitis and led to weight loss and reduction of the production of antimicrobial peptides and other important chemokines.95,96 Administration of Trp in the diet attenuates inflammation and protects against colitis symptoms.