In a piglet model of DSS-induced colitis, adding extra TRP to their regular diet improved clinical symptoms of colitis, increased piglet weight, and reduced intestinal permeability, which was possibly related to the reduced expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-6, interferon (IFN)-γ) and apoptosis initiators (caspase-8, Bax)51. This evidence concerns the gene IFNG and colitis.