The present invention provides materials and methods for inducing ion secretion and/or for treating cystic fibrosis. In one embodiment, the composition comprises glucose and/or a non-metabolizable glucose analog and/or non-structural protein (NSP4), a NSP4 peptide, or a NSP4 toxoid as the active ingredient, formulated with pharmaceutically-acceptable carriers. In a preferred embodiment, the composition is in a form of an aerosol preparation for intranasal and/or pulmonary administration, and is used to stimulate chloride and fluid secretion in nasal, tracheal and/or bronchial epithelium.