TABLE 2.

The major species-level taxa identified in this study (average relative abundance > 0.005).

Species	All average	COPD average	Healthy average	Fold change	FDR P-value
Prevotella intermedia	0.005	0.006	0.005	1.191	0.319
Prevotella melaninogenica	0.060	0.057	0.071	0.801	0.342
Prevotella pallens	0.013	0.012	0.017	0.700	0.0140*
Streptococcus pseudopneumoniae	0.017	0.020	0.004	5.667	0.222
Streptococcus salivarius	0.013	0.015	0.004	3.664	0.277
Streptococcus thermophilus	0.027	0.030	0.014	2.228	0.809
Haemophilus influenzae	0.043	0.052	0.008	6.779	0.617
Haemophilus parahaemolyticus	0.009	0.010	0.004	2.564	0.204
Haemophilus parainfluenzae	0.012	0.009	0.020	0.474	0.0074**
Neisseria meningitidis	0.009	0.009	0.008	1.044	0.128
Neisseria mucosa	0.007	0.008	0.002	4.452	0.785
Neisseria perflava	0.011	0.012	0.005	2.391	0.742
Neisseria subflava	0.017	0.012	0.036	0.330	0.0415*
Fusobacterium nucleatum	0.016	0.013	0.027	0.495	0.139
Fusobacterium periodonticum	0.014	0.012	0.022	0.531	0.0199*
Pseudomonas aeruginosa	0.016	0.020	0.000	NA	0.105
Moraxella catarrhalis	0.030	0.038	0.001	28.947	0.275
Veillonella parvula	0.005	0.004	0.010	0.439	0.208
Porphyromonas gingivalis	0.010	0.009	0.015	0.570	0.282
Campylobacter concisus	0.006	0.006	0.007	0.902	0.233

P-value was calculated using Wilcoxon rank-sum test. ***FDR P < 0.001; **P < 0.01; *P < 0.05.