Table 2. Comparison of respiratory health with stable and exacerbated chronic lung disease.

	Health	Chronic Lung Disease (Stable)	Chronic Lung Disease (Exacerbation)
Primary ecological determinant of community composition	Immigration/elimination	Mild: Immigration/elimination Severe: Regional growth conditions	Regional growth conditions
Respiratory dysbiosis	Absent	Moderate, varies with disease severity	Severe
Airway inflammation	Absent/mild Proportionate to microbial burden	Increased Proportionate to microbial burden	Increased Disproportionate to microbial burden