Microbiota composition and disease severity in bronchiectasis

Abstract

The microbes present in the lower airways are strongly implicated in the development, progression, and severity of many types of chronic lung disease. Complex and bidirectional relationships exist between the airway environment, the composition of the lung microbiota, and rate and nature of accumulated damage. Understanding these interactions, and their implications for bronchiectasis, is challenging. The development of local immune regulation in early life, and the effects of host mutations, such as those affecting mucin properties, both influence airway microbiology. As disease develops, there is a divergence from healthy airway microbiology, while in later disease, changes in the physicochemical characteristics of the lungs due to inflammation and remodelling, as well as exposure to antibiotics and other therapies, are central in defining more marked changes in airway microbiology. Throughout this process, the impact of altered airway microbiology of respiratory health is influenced by both the behaviour and immune-modulatory traits of pathogenic taxa, and the interactions of these key species with the wider airway microbiota. Recent technological advances present opportunities for detailed characterisation of the airway microbiome, allowing us to dissect the relationships between airway microbiology and respiratory health. The ways in which this basic research can help to provide mechanistic insight, prognostic information, and a basis for improved clinical care, will be discussed.