This patent discloses compositions and methods of use thereof to normalize the blood glucose levels of patients with type 2 diabetes. It relates particularly to a plasmid comprising a chicken .beta. actin promoter and enhancer; a modified GLP-1 (7-37) cDNA (p.beta.GLP1), carrying a furin cleavage site, which is constructed and delivered into a cell for the expression of active GLP-1.