Food allergy and probiotics in childhood.

Food allergy is a frequent problem in childhood and its prevalence is increasing. In most cases food allergy is an IgE-mediated hypersensitivity response that cause skin reactions as urticaria. Subacute or chronic disorders have generally a not IgE mediated mechanism. Milk is the most common food allergen in USA and UK followed by egg, peanut and walnuts. Sensitization to milk or egg in infancy is associated with an increased risk to develop house dust mite sensitization and asthma later in childhood. Commensal gut flora play a role in induction of oral tolerance and the importance of the intestinal microbiota in the development of food allergy is essential in early ages, when the mucosal barrier and immune system are still immature. Probiotics interact with the mucosal immune system by the same pathways as commensal bacteria. Recent study show that probiotic bacteria induced in vivo increased plasma levels IL-10 and total IgA in children with allergic predisposition. Many clinical studies reporting significant benefits by probiotics supplementation in food allergy prevention and management but not everyone agree on their effectiveness. These differences are probably related to differences in selected populations and in probiotic strains used.