Importance of gut hormones in gastrointestinal, metabolic, and malignant diseases

Purpose of review: This review highlights the advances over the past year on the role of alimentary hormones in gastrointestinal and metabolic diseases and in malignancies. This is appropriate at this time because a new era of discovery has been entered in this area, particularly with regard to targeting hormone receptors for imaging and therapeutics with either peptide analogues or small nonpeptide drugs. This had been accomplished only with long-acting somatostatin analogues a decade ago. Now it is true for ghrelin, gastrin, cholecystokinin, motilin, glucose-dependent insulinotropic hormone, glucagonlike peptide (GLP) 1, GLP-2, and peptide tyrosine tyrosine (PYY). Recent findings: Advances in the areas of cancer, diabetes, obesity, and gastrointestinal motility and malabsorption disorders have all been recorded over this period. Both peptide and small drug ghrelin agonists have been developed that may be valuable for treating anorexia, which is a major problem in patients with cancer and other disorders. Understanding of the role of gastrin and cholecystokinin gene products in cancer has improved, and inhibitors of these peptides are likely to be useful as chemopreventive agents or as adjunctive therapeutics in cancer. Motilin agonists have already found their way into the clinic for treating diabetic gastroparesis and other motility disorders. Long-acting GLP-1 and GLP-2 agonists are likely to benefit patients with type 2 diabetes mellitus and short bowel syndrome, respectively. Finally, long-acting agonists for different peptide tyrosine tyrosine such as obesity and diarrhea. Summary: These advances are indicative of the targeted approach to new therapeutics that is being seen in all aspects of medicine, and an expansion of this approach can be expected in the future.