Table 2.

Baseline characteristics of fecal samples

	Unit	Control group (n = 32)	COPD patients (n = 32)	p-value
Ammonia	µg/g	32.0 (24.3, 44.5)	27.0 (23.5, 33.5)	0.103
Calprotectin	µg/g	88.8 (32.8, 187.2)	97.9 (32.1, 320.5)	0.705
pH		6.7 ± 0.6	6.7 ± 0.7	0.948
Acetic acid	mg/g	46.4 (31.5, 57.5)	40.9 (28.8, 65.3)	0.803
Propionic acid,	mg/g	12.6 (9.4, 18.8)	11.4 (7.8, 18.6)	0.373
Butyric acid	mg/g	11.9 (6.4, 20.7)	9.3 (6.4, 15.3)	0.412
Isobutyric acid	mg/g	2.4 (1.7, 2.8)	1.8 (1.2, 2.3)	0.040
Valeric acid	mg/g	2.2 (1.4, 2.8)	2.0 (1.4, 2.5)	0.403
Isovaleric acid	mg/g	3.7 (2.7, 4.2)	2.7 (1.7, 3.5)	0.018
Total SCFAs	mg/g	76.4 (52.5, 102.9)	71.8 (54.8, 116.8)	0.946
Bristol stool chart		4.0 (4.0, 5.8)	4.0 (4.0, 6.0)	0.303

Data are presented as mean ± SD or median (interquartile range). SCFAs = short chain fatty acids