Abstract: The invention provides methods and compositions for the diagnosis, prognosis and treatment of respiratory tract diseases. Specifically, the invention provides diagnosis, prognosis and treatment of respiratory infections using bitter and sweet taste signal transduction pathways. In one aspect, the invention relates to a method for treating a respiratory infection by administering a composition to the respiratory tract of a subject in an amount capable of activating bitter taste signaling and/or inhibiting sweet taste signaling. The composition comprises at least a bitter receptor agonist and, optionally, a pharmaceutically acceptable carrier for delivering the composition to the respiratory tract. In another aspect, the invention relates to a composition for treatment of a respiratory infection. Such composition comprises at least a bitter receptor agonist and, optionally, a pharmaceutically acceptable carrier for delivering the composition to the respiratory tract.