By Allergen Bureau

Markers of allergy risk may be present at birth

Our understanding of the factors involved with childhood allergy development has been advanced by a new study that has analysed the microbiota of meconium – a baby’s first stool after birth. Babies whose first stool did not contain a normal profile of certain biochemicals and gut bacteria were found to be at a significantly higher risk of developing allergies by the age of one.

The composition of meconium reflects the substances that entered the baby’s mouth in late pregnancy and provides the starting material for the initial gut microflora. Reduced colonization of beneficial early-life microbes is linked to a number of IgE-mediated disorders such as food allergies, eczema and asthma.

The new study, carried out by researchers at the University of British Columbia in Vancouver, analysed the meconium of 100 babies who had been part of a larger, ongoing Canadian study of child development. Risk of allergy was measured by a skin prick test.

To define the factors that may affect microbiota development, the researchers quantified the number of detected metabolites in the meconium and used that measure of metabolite richness to estimate diversity. Atopic infants had a significantly less metabolically-rich meconium at birth compared with that of non-atopic infants, suggesting that differences that support microbiota development and, in turn, influences immune development may already exist at birth.

These findings, published in the New Scientist, highlight the potential to promote beneficial microbiota and healthy immune development before or at birth to decrease risk of allergic disease.