Airway Microbiome in Asthma: Relationships to Asthma Phenotype and Inhaled Corticosteroid Treatment

There are new, very sensitive methods for detecting bacteria. These methods show that hundreds of millions of microbes (organisms that can only be seen with microscopes), especially bacteria, live in healthy people. The collection of different microbes found in a site is called a "microbiome." The investigators know that microbiomes of the skin, sinuses, mouth, gastro-intestinal tract, etc. differ from each other. The make-up of the microbiome - which bacteria are found in a site - may be necessary for good health. For example, the microbiome of the mouth is different in people with inflammation of the gums (periodontitis), and the microbiome of the bowel is different in people with inflammation of the intestinal tract (inflammatory bowel disease). The purpose of this research study is to find out if the microbiome in the lungs is different in healthy people without asthma compared to people with asthma. This study will also find out if the microbiome of the lungs changes when people with asthma take a daily "controller" medication called an inhaled corticosteroid.

Two broad specific aims of this study are: 1)To evaluate whether the microbiota of the bronchial airways in atopic asthmatics and atopic healthy controls differ in microbial diversity, richness, evenness, or composition of specific bacterial taxa. 2) To determine whether inhaled corticosteroid treatment alters bronchial microbial community composition in asthmatics.