TABLE 1:

Subjects’ clinical and bronchoalveolar lavage characteristics.

	Infants with CF* whose BAL samples yielded > 1000 16S rRNA gene reads (n=13)	Infants with CF whose BAL samples yielded < 1000 16S rRNA gene reads (n = 8)	p†	Control infants whose BAL samples yielded > 1000 16S rRNA gene reads (n=9)	p‡
Clinical characteristics
Male, n (%)	7 (54%)	4 (50%)	1	7 (78%)	0.57
Age (months), median (25th-75th ile)	1.8 (1.5–3.1)	2.0 (1.7–2.4)	0.54	5.0 (2.9 – 8.2)	0.007
P.Phe508del homozygous, n (%)	11 (85%)	5 (63%)	0.53	-	-
Diagnosis by newborn screening, n (%)	11 (85%)	6 (75%)	1	-	-
Prior antibiotic exposure, n (%)	7 (54%)	4 (50%)	1	-	-
Respiratory symptoms at BAL, n (%)	5 (38%)	1 (13%)	0.43
Antibiotics at BAL, n (%)	4 (31%)	0	0.24
Bronchoalveolar lavage features
Bacterial colony forming units/mL, median (25th – 75th ile)	1.94 × 104 (6 × 103 – 6.3 × 105)	645 (0.75–1635)	0.008	5.83 × 104 (1.11 × 104— 2.02 × 105)	0.9
Interleukin-8 (pg/mL), median (25th – 75th ile)	79 (56–195.6)	30 (25–36) §	0.03	41 (22.1–71) §	0.21
Neutrophil elastase (mcg/mL), median (25th – 75th ile)	6.2 (2.5–16.1)	4.2(2.5–8.6) **	0.37	2.5 (2.5–5.1) §	0.33

^*CF: Cystic fibrosis

^†Comparison between infants with CF whose bronchoalveolar lavage samples yielded greater than or fewer than 1000 16S rRNA gene sequence reads respectively. Chi-square test for categorical variables; t-test for parametric continuous variables; Whitney test for non-parametric continuous variables

^‡Comparison between infants with CF and control infants whose bronchoalveolar lavage samples yielded greater than 1000 16S rRNA gene sequence reads. Chi-squared test for comparison of categorical variables; Mann Whitney test for comparison of continuous variables

^§Missing data from three participants

Missing data from one participant

^**Missing data from two participants