Babies and young children are less likely to develop allergy-related asthma if their guts have mature communities of bacteria, a major conference has heard.
Australian research, presented at the European Respiratory Society International Congress in Milan, Italy, yesterday, found that babies with more mature gut microbiota at one year old were less likely to experience allergy-related wheezing at one and four years old.
A team from Deakin University, Geelong, analysed data from the Barwon Infant Study (BIS), which recruited 1,074 babies between 2010 and 2013 in Australia.
For this study, research fellow Dr Yuan Gao and her colleagues looked at the bacteria present in faecal samples collected from the BIS babies one month after birth, six months and one year.
At the one-year and four-year reviews, the BIS investigators asked the parents if their children had developed allergy-related wheeze or asthma in the previous 12 months. The team also carried out skin-prick tests to see if the children had allergic reactions to any of ten foods and any airborne substances that can trigger an allergic response, such as rye grass or dust.
In a randomly selected sub-group of 323 children, the BIS team used a DNA sequencing technique to identify and characterise the gut microbiota, calculating the microbiota-by-age z-score (MAZs), to estimate of the maturity of the children’s gut microbiota.
Dr Gao said: “Our studies on the Barwon Infant Study showed that a more mature infant gut microbiota at one year of age was associated with a lower chance of developing food allergies and asthma in childhood. This appeared to be driven by the overall composition of the gut microbiota rather than specific bacteria. We then hypothesised that advanced maturation of the infant gut microbiota in early life is associated with decreased risk of allergy-related wheeze in later childhood.
“If MAZ increased within a certain range, known as standard deviation, it halved the risk of allergy-related wheeze at both these ages. In other words, the more mature the gut microbiota, the less likely were the children to have allergy-related wheeze. We did not find a similar association with MAZ scores at one or six months.”
The mechanisms by which mature gut microbiota contribute to preventing allergy-related disease is not completely understood, although Dr Gao said given the complex origins and development of both gut microbiota and the infant immune system, it is likely the protective effect of a healthy gut microbiota occurs as a result of communities of bacteria acting in multiple different ways, rather than via one particular mechanism.
“We hope that by understanding how the gut microbiota improves the immune system, new ways of preventing allergy-related disease such as asthma can be developed,” she said.
The researchers are planning to recruit 2000 children from Australia and New Zealand to a new clinical trial, called ARROW, to see if giving young children a mixture of dead bacteria, taken orally, can protect them from wheezing illnesses or asthma by boosting a healthy immune response to viral infections.
“ARROW has the potential to dramatically improve the health of children with recurrent wheeze and asthma,” said Dr Gao.
Abstract no OA1434 – Yuan Gao et al. Gut microbiota maturity in infancy and atopic wheeze in childhood. Sunday 10 September 2023.
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