New Asthma Biomarkers Identified From Lung Bacteria

By Jane Farrell

Until now, research on the microbiome – the system of good and bad bacteria in the body – has been focused on digestive issues. But a new study shows that it may affect respiratory conditions as well.

“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,” said Dr. Patricia Finn, the Earl M. Bane Professor of Medicine at the University of Illinois at Chicago.

The research from Finn and her colleagues in the UIC College of Medicine suggests that the lung microbiome plays a significant role in asthma severity and response to treatment.

In a group of clinically similar patients with asthma, researchers identified two asthma phenotypes by assessing the microbiome and airway inflammation. The patients were ages 18 to 30 with mild or moderate atopic asthma.

These two phenotypes, called asthma phenotype one and two, or AP1 and AP2, are distinguished by the prevalence and dominance of different bacteria in the lung. When compared, patients in the two groups performed differently on pulmonary function tests.

AP1 was associated with less severe asthma; AP2 was associated with increased more severe asthma.

“This tells us the microbiome has relevance beyond the gut, and that it is a potential biomarker for asthma,” said Dr. David Perkins, professor of medicine and surgery at UIC, who jointly operates the lab with Finn.

“The data suggest that further study of the microbiome may help to develop more personalized treatment recommendations for patients with asthma,” said Finn, the senior author on the paper, which is published in PLOS ONE.

Finn says that asthma research has increasingly focused on the differences between seemingly similar patients, and that this study adds to the growing body of evidence that patients benefit from precision medicine approaches to common chronic diseases, such as asthma.

“If we can better understand how the individual’s lung microbiome affects asthma and identify likely microbial culprits, we may get to a point where we can predict and control asthma development and severity by shifting the microbiome early in life,” Finn said. “This could be as simple as diet, probiotics or medication.”

A second study from the Finn-Perkins lab at UIC, recently published in the American Journal of Respiratory Cell and Molecular Biology, showed that even prior to birth, exposure to specific compositions of bacteria may elicit an inflammatory immune response that could predispose individuals to asthma.