Asthma linked to bacterial communities in the airway

A new UCSF-led study has found that asthma may have a surprising relationship with the composition of the species of bacteria that inhabit bronchial airways.

This finding could suggest new treatment or even potential cures for the common inflammatory disease. Using new detection methods, researchers learned that the diversity of microbes inside the respiratory tract is far vaster than previously suspected – creating a complex and inter-connected microbial neighborhood that appears to be associated with asthma, and akin to what has also been found in inflammatory bowel disease, vaginitis, periodontitis, and possibly even obesity.

"People thought that asthma was caused by inhalation of allergens but this study shows that it may be more complicated
than that – asthma may involve colonization of the airways by
multiple bacteria,`` said study co-author Homer Boushey, MD,
a UCSF professor of medicine in the division of Pulmonary and
Critical Care Medicine.

In their three-year pilot project, the scientists collected samples from the airway linings of 65 adults with mild to moderate asthma and 10 healthy subjects. Then, using a tool that can identify approximately 8,500 distinct groups of bacteria in a single assay, the scientists profiled the organisms present in each sample to look for relationships between bacterial community composition and clinical characteristics of the patients` asthma.

The researchers found that bronchial airway samples from
asthmatic patients contained far more bacteria than samples from
healthy patients. The scientists also found greater bacterial
diversity in the asthmatic patients who had the most hyper-
responsive or sensitive airways (a feature of asthma).