Immunonutrition: Diet Diversity, Gut Microbiome and Prevention of Allergic Diseases.

Allergic diseases are increasing both in morbidity and mortality. Genetic, environmental, and dietary factors may all be involved in this increase. Nutrition during pregnancy, breastfeeding, and early life may play a particularly important role in preventing allergic diseases. Based on current systematic reviews, the intake of specific nutrients has failed to prevent allergic disease. Prevention strategies have shifted their focus to the overall diet which can be described using diet diversity. Infant and maternal diet diversity in pregnancy has been associated with reduced allergy outcomes in childhood. Overall, diet also seems to have a marked effect on the microbiome compared to single foods. Factors that may negate the allergy-preventative effect of overall diet diversity include the addition of emulsifiers, advanced glycation end-product content, and overuse of commercial baby foods. There is a need to perform randomized controlled trials using overall dietary intake to support international food allergy guidelines. These studies should ideally be conducted by multi-professional teams.