Probiotics for allergic respiratory diseases--putting it into perspective.
Respiratory allergies include allergic rhinitis, sinusitis and asthma. Increasing attention on pathogenesis of allergic airway diseases has given rise to "atopic march" hypothesis i.e. clinical features of atopic eczema occur first and precede the development of asthma and allergic rhinitis. The "hygiene hypothesis" proposes that the increase in allergic diseases reflects a decrease in infections during childhood. Clinical trials also suggest that the exposure to microbes through the gastrointestinal tract powerfully shapes immune function. Probiotics are live organisms which exert a beneficial effect in the prevention as well as treatment of allergic diseases through modification of immune system of host via gut ecosystem. Intestinal microbiota differs in infants who later develop allergic diseases, and feeding probiotics to infants at risk has been shown to reduce their rate of developing eczema. This has prompted studies of feeding probiotics in prevention as well as treatment of respiratory allergy. We hereby discuss the status of probiotics in respiratory allergy.