The presence of four specific types of bacteria in the gut during the earliest months of a child’s life could determine whether they go on to develop asthma, according to new research from Canadian scientists that may point toward a future preventative treatment for the condition.
The study, published in Science Translational Medicine, examined the microbiomes of 319 children and found that those lacking four particular bacterial strains at three months old faced a significantly higher risk of developing asthma by the age of three. The four bacteria in question — Faecalibacterium, Lachnospira, Veillonella and Rothia, collectively referred to as FLVR — appear to play a critical role in the early development of the immune system.
Researchers at the University of British Columbia and the Children’s Hospital in Vancouver compared the gut bacteria present in children at three months and again at one year of age, then assessed asthma risk at age three using wheeze measurements and skin allergy tests. The protective effect of the four bacteria was only observed in the three-month samples, not in those taken at one year old, suggesting the window of opportunity is narrow and that the first few months of life are particularly significant.
To investigate further, scientists introduced the bacterial combination to previously germ-free mice and found it reduced airway inflammation in their offspring, providing additional evidence that the bacteria have a direct biological effect on respiratory health.
The human body contains bacteria, fungi and viruses that outnumber human cells by ten to one, and this collective ecosystem — known as the microbiome — is increasingly understood to have wide-ranging effects on long-term health outcomes. Experts in the field have suggested that ensuring children have the right microbial environment at the right stage of development may prove to be one of the most effective strategies for reducing rates of allergies and asthma.
Dr Stuart Turvey, one of the lead researchers on the project, said the longer-term ambition is to develop a supplement containing the FLVR bacteria that could be given to infants to reduce their risk of developing asthma later in childhood. He was careful to stress, however, that clinical application remains some way off.
“I want to emphasise that we are not ready for that yet — we know very little about these bacteria,” he said, “but our ultimate vision of the future would be to prevent this disease.”
Asthma affects millions of children worldwide and remains one of the most common chronic conditions in early childhood. Researchers say that if the bacterial link can be confirmed through further studies, it could reshape how the medical community approaches prevention in the years ahead.
