A method of treating Gauchers disease in a subject in need thereof is provided. The method comprising orally administering to the subject a therapeutically effective amount of recombinant glucocerecbrosidase (GCD) comprised in plant cells, wherein said therapeutically effective amount of GCD corresponds to 1-1920 units/Kg/14 days, thereby treating Gauchers disease. Also provide unit dosage forms which comprise the glucocerecbrosidase (GCD) comprised in plant cells.