Image of the lungs to illustrate individuals with chronic obstructive pulmonary disease (COPD), which can be influenced by genetic variation in EPAS1 gene, which impacts oxygen saturation in the blood
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Babies and young children with more mature gut bacteria are less likely to develop allergy-related wheezing or asthma, according to research presented yesterday at the European Respiratory Society International Congress in Milan.

Yuan Gao, a research fellow at Deakin University, Geelong, Australia, presented the study.

“We found that if babies had more mature gut microbiota when they were one year old, they were less likely to have an allergy-related wheeze at one and four years old,” said Gao.

Communities of bacteria, known as microbiota, or the microbiome, develop in the human body during the early years of life and are involved in synthesizing vitamins and boosting the immune system. They may also play affect disease processes such as inflammatory bowel disease and stomach ulcers.

Babies already have some microbiota in their guts from their mothers when they are born. The diversity of microbiota increases and matures as they grow older and are exposed to more different types from sources such as other children, animals, and different foods.

The Barwon Infant Study (BIS), which has been running in Australia since 2010, recruited 1074 babies between 2010 and 2013, and researchers have been following the babies as they grow. For this current study, Gao and her colleagues looked at the bacteria present in fecal samples collected from the BIS babies one month, six months, and one year after birth.

At the one-year and four-year postnatal reviews, the BIS investigators asked the parents to report on whether their children had developed allergy-related wheeze or asthma in the previous 12 months. The researchers also did skin-prick tests to see if the children had allergic reactions to any of ten foods and airborne substances that can trigger an allergic response, such as rye grass or dust.

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 hypothesized that advanced maturation of the infant gut microbiota in early life is associated with decreased risk of allergy-related wheeze in later childhood.”

In a randomly selected sub-group of 323 children, the BIS team used a DNA sequencing technique to identify and characterize the gut microbiota. They calculated ‘microbiota-by-age z-score’ (MAZs), which is a mathematical estimate of the maturity of the children’s gut microbiota.

“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. For instance, it might be possible to suggest ways of advancing the maturation of gut microbiota in early life, which would lead to fewer children developing asthma and other allergy-related diseases in the future. With so little known about why babies develop allergies and asthma, more research is needed.”

The researchers are now planning to recruit 2000 children from Australia and New Zealand to a new clinical trial, called ARROW, to see whether 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. Viruses are the commonest causes of childhood illnesses and can lead to chest infections and wheezing.

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