A NEW study has revealed that the composition of the human milk microbiome is significantly influenced by both the mother’s allergic disease and the season in which the infant is born. The research highlights how maternal allergies and environmental factors shape the microbial composition of breast milk, which in turn plays a crucial role in shaping an infant’s developing immune system.
Led by Jie Ma and colleagues, the study analysed milk samples from 196 allergic mothers at three and six months postpartum, using full-length 16S rRNA gene sequencing to identify microbial variations. The results showed that the composition and diversity of the milk microbiome changed over time and was strongly affected by the season in which the infant was born. This seasonal impact was found to alter five of the most abundant bacterial taxa present in human milk.
Additionally, the study found that different allergic disease phenotypes, such as allergic rhinitis, asthma, atopic dermatitis, and food allergies, were associated with distinct microbial signatures in breast milk. Infant feeding mode also played a role, with formula-fed infants showing a reduced presence of several key oral bacteria in their mothers’ milk.
The findings underscore the complex interplay between maternal health, environmental factors, and infant nutrition. Since early infancy is a critical period for immune development, understanding how these factors influence breast milk microbiota could help inform strategies to support infant gut health and immune function.
The study highlights the importance of considering both maternal allergic history and birth season in future microbiome research. It also raises intriguing questions about whether tailored interventions, such as probiotic supplementation or maternal dietary modifications, could help optimise breast milk composition for infants at higher risk of allergies.
Aleksandra Zurowska, EMJ
Reference
Jie M et al. Maternal Allergic Disease Phenotype and Infant Birth Season Influence the Human Milk Microbiome. Allergy. 2024;DOI: 10.1111/all.16442.
