There has been mounting evidence that there is a bacterial element to the development of asthma, and now a new study lends even more support to this theory. Researchers have found that children who have low levels of four specific types of bacteria at the age of three months have an increased risk of going on to develop asthma later in life.
After collecting stool samples from over 300 children at both three months and one year of age, as well as details of their health and allergies at one, three and five years old, the researchers found a “very” statistically significant association between the absence of certain types of bacteria and the potential of developing asthma. This research could help doctors identify children at risk from an early age, and even raises the potential of creating a probiotic that could prevent the disease.
Asthma is a growing issue, with more and more adults and children being diagnosed with the disease, which still kills around three people a day in the U.K. alone. The causes behind it have, however, remained a little sketchy. But research and observations from the last decade have started to implicate the microorganisms that call our bodies home. Our microbiome is made up of trillions of bacteria and viruses, and modern medicine has only recently begun revealing how they impact our health.
This new study, published in Science Translational Medicine, seems to show that babies who have low levels of or lack four bacteria – Faecalibacterium, Lachnospira, Veillonella, and Rothia – have more of a risk of developing asthma later on in life. But it is not simply the presence or absence, but rather the timing that is significant. That's because by the age of one, the microbiomes of all the babies in the study looked fairly similar. So it seems that it could be more of a matter of getting the right bacteria at the right time, and that there is a critical window for this when the children are a few months old.
In further experiments, the researchers examined the effects of giving mice raised in a bacteria-free environment a microbiome without these specific bacteria. Bolstering their previous findings, the mice went on to develop inflamed lungs indicative of asthma. Yet when they mixed the missing bacteria into the mice’s gut, the symptoms of the disease started to go away again.
“For a number of years, exposure to microbes has been linked with protection against asthma, a classic example is growing up on a farm and drinking raw milk,” Dr. Benjamin Marsland, who was not involved in the research, told BBC News. “This new study adds weight to these observations and supports the concept that there are certain developmental windows in early life, where it's really important to get the right signals.”
The paper raises the possibility of developing a probiotic containing the four microorganisms that could be given to babies thought to be at risk, though the researchers stress that while this is hypothetically possible, it’s still a big unknown whether or not it would work in real life. What is much more likely is that doctors will now be able to test infants for the presences or absence of these bacteria, and then monitor children who have lower numbers of the microorganisms.