Babies and young children with a diverse and more mature community of bacteria present in their gut are less likely to develop wheezing or asthma related to allergies, finds study.

Bacteria known as microbiota develop in the human body during the early years of life and are associated with a lower chance of developing food allergies and asthma in childhood.

Microbiota, which babies already have in their guts from their mothers when they are born, helps the body in synthesising vitamins and boosting the immune system.

Our studies 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 wheezing in later childhood, said Dr Yuan Gao, a research fellow at Deakin University, Geelong in Australia.

For the study, the team randomly selected 323 children and looked at the bacteria present in their faecal samples one month after birth, six months and one year. 

At the one-year and four-year postnatal reviews, the investigators asked the parents to report whether their children had developed allergy-related wheezing or asthma in the previous 12 months.

The researchers used a DNA sequencing technique to identify and characterise the gut microbiota. They also calculated the ‘microbiota-by-age score (MAZs), which is a mathematical estimate of the maturity of the children’s gut microbiota by doing DNA sequencing of 323 children randomly.

If MAZ increased within a certain range, known as standard deviation, it halved the risk of allergy-related wheezing 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, said Dr. Gao.

“We hope that by understanding how the gut microbiota improves the immune system, new ways of preventing allergy-related diseases such as asthma can be developed,” she added.

Meanwhile, researchers are also planning to recruit 2,000 children from Australia and New Zealand to a new clinical trial 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.