Australia is a country with an especially high prevalence of allergic diseases, where a pronounced rise in eczema and food allergies has been seen in the past decade. What are the factors behind this increase in allergic disease? To answer this question, Dr. Ralf Heine first delineates the risk factors, including genetics, epigenetic dysregulation, microbial and dietary factors. Next, Heine reviews the key findings on the influence of gut microbiota. Data from studies such as the GABRIELA and PARSIFAL trials indicate the protective effects of microbial diversity, a parameter that is also affected by mode of birth, gestational age and infant feeding.He then examines the role of infant feeding, including the introduction of complementary feeding, in the prevention of allergies. By focusing on atopic dermatitis, Heine discusses the effects of probiotics, prebiotics, long-chain polyunsaturated fatty acids and vitamin D on this signature allergic disorder. Based on this clinical evidence, Heine establishes a series of pre- and postnatal recommendations for allergy prevention.