Features of the bronchial bacterial microbiome associated with atopy, asthma, and responsiveness to inhaled corticosteroid treatmentOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined the bacterial community composition of the bronchial airway, sampled by protected bronchial brushing, in relation to atopic asthma. The researchers used 16S rRNA gene sequencing to characterize the bronchial bacterial microbiome and inferred community-level functional profiles from the sequencing data. They compared microbiome composition across groups and examined associations with clinical and inflammatory features, including type 2-related inflammation markers and the change in airway hyperresponsiveness following six weeks of inhaled fluticasone treatment.
Who was studied?
The study included 42 adults with steroid-naive atopic asthma, 21 adults with atopy but no asthma, and 21 nonatopic healthy control subjects. All participants underwent bronchial brushing to obtain airway samples for bacterial profiling. The asthmatic group had not yet received corticosteroid treatment at the time of initial sampling, allowing comparison before and after six weeks of fluticasone.
What were the most important findings?
The bronchial microbiome differed significantly among the three groups. Asthmatic subjects were uniquely enriched in members of the Haemophilus, Neisseria, Fusobacterium, and Porphyromonas genera compared with the atopy-only and healthy control groups. These compositional differences suggest that microbiome features are more closely tied to the asthma phenotype itself than to atopy or aeroallergen sensitization alone.
What are the greatest implications of this study?
By comparing steroid-naive asthmatics, atopic non-asthmatics, and healthy controls, the study helps disentangle whether bronchial microbiome changes reflect asthma, atopy, or corticosteroid treatment. Enrichment of specific bacterial genera in asthmatic airways points to potential microbial targets or biomarkers relevant to asthma pathophysiology. The examination of microbiome relationships to corticosteroid responsiveness also raises the possibility that airway bacterial composition could inform understanding of treatment response in asthma.