New Research Links Asthma to Changes in Gut Microbiome

Asthma is one of the illnesses we frequently treat at Pediatric Associates of Northern Colorado. Over the last 40 years, the incidence of asthma has dramatically increased for unclear reasons. Now, new evidence has been published showing clear links between changes in the intestinal microbiome and the development of asthma.

One of the exciting frontiers in 21st century medicine is the exploration of the role the microbiome plays in health and disease. “Microbiome” is the name given to the trillions of bacteria and fungi that live in and on our bodies. While the idea that all of our internal and external surfaces are coated with a complex ecosystem of microorganisms can make one feel a bit squeamish, research over the past decade has shown that these microbes help to maintain our state of good health when they are present in the correct places in the appropriate combinations of species.

Conversely, evidence is mounting that derangements in these populations are associated with inflammatory, autoimmune, allergic, cardiovascular, dental and gastrointestinal diseases. One set of such associations has recently been documented in the case of childhood asthma.

We have known for the last 15 years or so that a child is more likely to develop asthma if they have had more courses of antibiotics for things like strep throat and ear infections in their early childhood. It has been assumed that this was related to destruction of the body’s microflora by these antibiotics which then changes the way our immune system responds to antigens. In the case of asthma, it seems that the derangement in the microbiome causes the immune system to “overreact” to environmental antigens, triggering the bronchospasm and wheezing characteristic of asthma.

Now we have evidence of specific bacterial strains in the guts of children which appear to be protective against the development of asthma. Microbiologist Brett Finlay at the University of British Columbia presented evidence that children deficient, at the age of three months, in four relatively rare bacteria — Faecalibacterium, Lachnospira, Rothia and Veillonella — were 20 times more likely than those playing host to these species to develop asthma and allergies. Further, the presence of a microscopic fungus known as Pichia in the stools of children at 3 months of age put them at further increased risk for the development of asthma.

There is a ways to go before we understand the best way to introduce helpful protective bacteria into our microbiomes and drive out species that increase the risk of disease, but this work represents an important step in the biomedical quest to treat and even prevent asthma. It also establishes a methodology that will allow researchers to determine the association between other diseases and our microflora populations, opening the door to further probiotic interventions to preserve health and prevent disease. Exciting stuff.