Table 1.

Studies of the lung microbiome in COPD

Study	Subjects (n)	Sample	Key findings
Hilty et al. 2010 [21]	8 Control	BAL/Brush	Pathogenic bacteria, e.g. H. influenzae in asthma and COPD subjects
	11 Asthma
	5 COPD
Charlson et al. 2010 [22]	29 Smoker	Pharynx	Different regions of pharynx have different microbial communities which are changed by smoking
	33 Non-smoker
Erb-Downward et al. 2011 [23]	9 Control/	BAL	Core pulmonary microbiota in BAL & lung tissue
	5 COPD
	6 severe COPD
Sze et al. 2012 [24]	8 Control	Lung tissue	Differences in bacterial communities in the same lung
	8 COPD
	8 severe COPD
	8 Cystic fibrosis
Pragmann et al. 2012 [25]	10 Control	BAL	Detectable bacterial communities in lung tissue that changes in severe COPD
	22 COPD
Morris et al. 2013 [15]	32 Smoker	Oral wash	Mouth communities different in smoker
	30 Non-smoker