Microbiome in interstitial lung disease: from pathogenesis to treatment target

Purpose of review This review summarizes current knowledge of the role of the lung microbiome in interstitial lung disease and poses considerations of the microbiome as a therapeutic target. Recent findings Although historically considered sterile, bacterial communities have now been well documented in lungs in health and disease. Studies in idiopathic pulmonary fibrosis (IPF) suggest that increased bacterial burden and/or abundance of potentially pathogenic bacteria may drive disease progression, acute exacerbations, and mortality. More recent work has highlighted the interaction between the lung microbiome and the innate immune system in IPF, strengthening the argument for the role of both host and environment interaction in disease pathogenesis. In support of this, studies of interstitial lung diseases other than IPF suggest that it may be the host immune response, which shapes the microbiome in these diseases. Some clinical and mouse model data also suggest that the lung microbiome may represent a therapeutic target, via antibiotic administration, immunization against pathogenic organisms, or treatment directed at gastroesophageal reflux. Summary Evidence suggests that the lung microbiome may serve as a prognostic biomarker, a therapeutic target, or provide an explanation for disease pathogenesis in IPF.