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Introducing allergenic food at three months can speed up gut flora maturation

3 month old


Gut bacteria is linked to eczema, infant diet and caesarean section birth, according to research from King’s College, London.

The study published in The Journal of Allergy and Clinical Immunology, found that the introduction of allergenic foods at three months increases the abundance of gut bacteria in an infant‘s gut and speeds up the maturation of the gut flora, which can help in the development of a healthy immune system.

The Enquiring About Tolerance (EAT) study, led by researchers from King’s and Guy’s and St Thomas’ NHS Foundation Trust, and published last month, looked at how infant gut flora evolves during infancy. Gut bacteria is important because it plays a vital role in developing the human immune system in early life.

The researchers identified specific gut bacteria, which can indicate a predisposition for eczema. They also found a lower abundance and variety of gut bacteria in babies born by caesarean-section instead of the vaginal canal.

Gut flora was collected from 1,303 infants who were exclusively breastfed across England and Wales. The infants were enrolled at three months, and the researchers examined stool samples at enrolment, six months and twelve months. The infants were examined for eczema and food allergies up until age three.

Infants with a higher abundance of the gut bacteria Clostridium sensu stricto were much more likely to have eczema. 

Professor David Gawkrodger, a consultant dermatologist and trustee of the British Skin Foundation, said: ‘Since there seems to be a relationship between the type of bacteria in the gut and the development of eczema, the manipulation of the gut bacteria in early life might reduce the likelihood of eczema in babies predisposed to develop it.’

The researchers also examined other hygiene-related factors which may influence gut bacteria during the first year of life. These included mode of baby delivery, receiving antibiotics, exposure to pets and siblings.  Infant delivery mode was the only factor to strongly influence gut bacteria, with a reduced diversity of gut flora seen in those born via cesarean section. This is likely because vaginal birth exposes infants to more microbes from their mothers. 

At three months, the participants were introduced to allergenic foods such as cow’s milk, eggs, sesame, wheat and peanuts, alongside breast milk and compared to exclusive breastfeeding until six months of age. The researchers found that weaning from three months of age alongside breastfeeding speeds up the gut flora’s maturation.

Professor Carsten Flohr, the lead researcher from the School of Basic and Medical Biosciences, said, ‘We hope these findings improve our understanding of the role our gut microbiome plays in the development of the immune system from an early age.’