In IBD patients exacerbated by a HFD, IAA levels are reduced, but supplementation of IAA can upregulate the expression of sulfotransferase enzymes such as 3-phosphoadenosine 5-phosphosulfate synthase and solute carrier family 35 member B3 (Slc35b3), thereby enhancing intestinal mucin sulfation and protecting gut homeostasis, which effectively relieves colitis [58]. The gene discussed is SLC35B3; the disease is colitis.