• Posted September 11, 2023

Healthy, Diverse Infant Microbiome Could Shield Kids From Asthma

Babies who have more mature microbes in their gut are less likely to have allergy-related wheezing and asthma in early childhood, according to new research.

"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,"said Dr. Yuan Gao, a research fellow at Deakin University in Geelong, Australia.

"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,"Gao said.

Study findings were presented Sunday in Barcelona at a meeting of the European Respiratory Society.

The Barwon Infant Study (BIS) has been ongoing in Australia since 2010. More than 1,000 babies were recruited between 2010 and 2013 and researchers have been following them as they grow.

They studied the bacteria present in fecal samples collected from the babies at age 1 month, and again at 6 and 12 months.

At one- and four-year reviews, parents reported whether their children had developed allergy-related wheeze or asthma during the past year. The team also did skin-prick tests to see if children had allergic reactions to any of 10 foods as well as airborne substances such as rye grass or dust that can trigger an allergic response.

The researchers randomly selected 320 children and used a DNA sequencing technique to identify and characterize their gut microbiota.

"We found that if babies had more mature gut microbiota when they were 1 year old, they were less likely to have an allergy-related wheeze at 1 and 4 years old,"Gao said in a meeting news release.

The authors used a mathematical formula to estimate maturity of bacteria in the children's guts. If it increased within a certain range, it halved the risk of allergy-related wheezing at both 1 and 4 years of age. No similar association was found under age 1.

Communities of bacteria, known as microbiota, develop in the human body during early life. They help with certain processes, such as synthesizing vitamins and boosting the immune system. They can also play a role in inflammatory bowel disease and stomach ulcers.

Mothers pass some of these organisms to their babies. The diversity of microbiota increases and matures as children grow older and have different exposures.

It isn't completely understood how mature gut microbiota contribute to preventing allergy-related disease.

"Given the complex origins and development of both gut microbiota and the infant immune system, it is likely that 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,"Gao said.

Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal.

Researchers hope that by understanding how the gut microbiota improves the immune system, new ways to prevent allergy-related disease can be developed.

"For instance," Gao said, "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."

Researchers plan to recruit 2,000 children from Australia and New Zealand to a new clinical trial. Its aim is to see if a mixture of dead bacteria, taken orally, can protect young children from wheezing illnesses or asthma by boosting a healthy immune response to viral infections.

More information

The American College of Allergy, Asthma and Immunology has more on children and allergies.

SOURCE: European Respiratory Society, news release, Sept. 10, 2023