Described herein are methods and compositions for treatment of diabetes and/or obesity. Bitter oligopeptide molecules formulated for enteric delivery modulate signals involving receptors facing the lumen of the gastrointestinal tract, said signaling related hormones such as glucagon-like peptide-1 (GLP-1) and peptide tyrosine-tyrosine (PYY) that involve inhibition of gastric emptying and appetite. As a novel way to treat diabetes with limited adverse effects the described invention uses body's own endocrine system to treat diabetes, which is an advantage over current therapies that may simply provide disease management without cure or require more radical approaches such as surgical intervention