US researchers have recently discovered that lung microbiome plays a significant role in asthma severity and response to treatment.

Senior study author Dr. Patricia Finn from the University of Illinois at Chicago said the microbiome is the ecosystem of good and bad bacteria living in the body."Because the lungs continuously and automatically draw air and any number of environmental agents, into the body, the composition and balance of microbes in the lungs may have a profound effect on many respiratory conditions,” Finn added.Asthma is a chronic disease in which lung airways become swollen and narrow, making it difficult for air to move in and out of lungs.

Because people with asthma have inflamed airways, they experience a range of symptoms, including shortness of breath, coughing, wheezing and chest tightness.In a group of clinically similar patients with asthma, the team identified two asthma phenotypes by assessing the microbiome and airway inflammation. The patients were ages 18 to 30 with mild or moderate atopic asthma."This tells us the microbiome has relevance beyond the gut and that it is a potential biomarker for asthma," said another researcher Dr. David Perkins.

These two phenotypes, called asthma phenotype one and two, or AP1 and AP2, are demarcated by the prevalence and dominance of different bacteria in the lung. When compared, patients in the two groups performed differently on pulmonary function tests.In both AP1 and AP2, the associations between the composition of the microbiome and specific inflammatory cytokines were decreased after treatment with an inhaled corticosteroid, a common asthma therapy.The researchers suggested that ICS may function by dampening responses to microbes.The data suggest that further study of the microbiome may help to develop more personalised treatment recommendations for patients with asthma.The research is published in PLOS ONE journal.