Probiotics are live microorganisms that are normally present in the gut of a healthy individual. They are also known as "friendly bacteria" and have been used to help maintain the normal functioning of the immune system. They are safe and are commercially available in the form of yoghurt, sachets, chewable tablets or flavored capsules. Since a number of nasal and sinus disorders are related to allergy and improper functioning of the immune system, we hypothesize that regular use of probiotics may help improve chronic nasal and sinus symptoms by boosting immune responses.