Decrease colonic pH; inhibit growth of pathogens; improve integrity and function of colonic epithelial cells; anti-lipolysis; increase insulin sensitivity and energy expenditure; inhibit production of proinflammatory cytokines. Involved in diabetes, ulcerative colitis, radiation proctitis, Crohn's disease, colorectal cancer, Parkinson's disease, asthma. Here, INS is linked to Crohn disease.