While the microbiome has received significant attention due to its
impact on digestive health in recent years, its impact on lung disease remains
largely unexplored. According to experts, this is a big omission. The
microbiome is the ecosystem of “good” and “bad” bacteria
living in the body. Because the lungs continuously take in air and
environmental substances, the composition and balance of microbes in the lungs
can have a profound effect on many respiratory conditions. New research
suggests that the lung microbiome plays a significant role in asthma severity
and response to treatment.
Asthma is a chronic disease in which the airways narrow, making it difficult
for air to move out of and into the lungs. As people with asthma develop
inflammation in their airways, they experience a range of symptoms, including
shortness of breath, coughing, wheezing, and seizures. In a group of asthma
patients, researchers identified two disease phenotypes by assessing the
microbiome and airway inflammation. Patients aged 18-30 had mild or moderate
atopic asthma.
This suggests that the microbiome matters beyond the gut and is a potential
biomarker for asthma treatment, the authors say. These two phenotypes, called
asthma phenotype one and two, or AP1 and AP2, are due to the abundance and
predominance of different bacteria in the lungs. When compared, patients showed
different results when passing functional tests.
AP1 was associated with less severe asthma; there is a decrease in T – helper
cytokines and an increase in enterococcal bacteria, normal results of pulmonary
function tests. In contrast, AP2 was associated with increased pro-
inflammatory cytokines, taxa, and streptococcal bacteria, as well as worsened
lung test scores.
In both AP1 and AP2, associations between microbiome composition and specific
inflammatory cytokines decreased after inhaled corticosteroid treatment.
The data suggest that further study of the microbiome may help develop more
personalized treatment recommendations for patients with asthma, the authors
note. Asthma research is increasingly focusing on the differences between
seemingly similar patients, and this study adds to the growing body of evidence
that patients are benefiting from precise medical approaches to common chronic
conditions like asthma.
If we can better understand how the human lung microbiome affects asthma, it
will be possible to predict and control the development and severity of asthma
by influencing the microbiome early in life.
A second study showed that even before birth, exposure to specific bacterial
compounds can trigger an inflammatory immune response that may predispose
people to asthma. The lung microbiome potentially plays a role in many parts of
the body, including cord blood cells, which may influence the onset of the
disease or its symptoms.