This document discusses microbial dysbiosis in cystic fibrosis (CF) and non-CF bronchiectasis. It finds that: 1) The microbiota in CF and bronchiectasis is stable over time but becomes less diverse during exacerbations or with antibiotic therapy. 2) Pseudomonas aeruginosa colonization in bronchiectasis is associated with worse outcomes like increased mortality, hospitalizations, and lung function decline compared to those without P. aeruginosa. 3) Culture-independent studies show the microbiota in bronchiectasis includes traditional pathogens like Haemophilus and Pseudomonas as well as anaerobes like Prevotella and Veillonella. Microbiome diversity is reduced