The Importance of the Role of the Breast Milk Microbiota in the Development of Asthma in Children

Human breast milk, due to its rich composition that contains an optimal nutrient profile, essential vitamins and beneficial commensal bacteria, is considered the most important form of infant nutrition. In fact, research has demonstrated that breastfeeding confers numerous health benefits, including the stimulation of infants' immune system development and the attenuation of risk factors associated with allergic diseases. Certain components of breast milk, such as oligosaccharides, has been proven to promote the development of gut bacteria, immune tolerance and reduce inflammation. Bacteria such as Lactobacillus and Bifidobacterium have also been shown to support the intestinal barrier and enhance the immune system of newborns. However, the impact of other components of the breast milk microbiota on this process, and especially on the risk of developing allergic diseases, is poorly investigated. In this narrative review, we aim to summarize what is known so far about the impact of the breast milk microbiota and how changes in its composition affect the development of allergic diseases in the newborns. A more profound comprehension of the impact of these microorganisms on the maturation of the immune system could facilitate the establishment of more efficacious prevention strategies for asthma and other allergic diseases. This could contribute to the optimization of breastfeeding practices and potential microbiological interventions to support child health.