Extended Data Table 2. Antibiotics and probiotics.

3,678 antibiotic prescriptions in TEDDY microbiome study population by clinical center (top). Early probiotic supplementation in TEDDY clinical centers (bottom). Probiotic use was stratified in three categories: probiotics during first 4 weeks of life (Early probiotic), probiotics prior to the first stool sample (roughly at three months) but not first 4 weeks (Later probiotic), and no probiotics prior to the first stool sample (No probiotic). Data for probiotics are presented as N (percentage). Abx = antibiotics.

	US, Colorado	US, Georgia	US, Washington	Finland	Germany	Sweden
Subjects with abx prescriptions	93 (81.6%)	37 (88.1%)	54 (78.3%)	206 (92.4%)	56 (75.7%)	192 (73.6%)
Median number of abx per subject (25th and 75th percentile)	2 (1–6)	5 (2–9)	2 (1–4)	6 (3–11)	2 (0–5)	2 (0–4)
Number of abx by type (prescriptions per subject)
Amoxicillin	242 (2.12)	147 (3.50)	104 (1.51)	769 (3.45)	45 (0.61)	134 (0.51)
Cephalosporins	87 (0.76)	65 (1.55)	31 (0.45)	127 (0.57)	51 (0.69)	23 (0.09)
Macrolide	54 (0.47)	35 (0.83)	47 (0.68)	203 (0.91)	33 (0.45)	23 (0.09)
Penicillin	6 (0.05)	2 ( 0.05)	3 (0.04)	17 (0.08)	13 (0.18)	412 (1.58)
Other	76 (0.67)	80 (1.90)	33 (0.48)	521 (2.34)	77 (1.04)	154 (0.59)
Total	465 (4.08)	329 (7.83)	218 (3.16)	1,637 (7.34)	219 (2.96)	746 (2.86)
Probiotic use in early life
Early probiotic	0 (0.0%)	1 ( 2.9%)	0 (0.0%)	63 (30.7%)	7 (10.0%)	13 (5.6%)
Later probiotic	1 (0.9%)	1 ( 2.9%)	2 (3.3%)	16 (7.8%)	8 (11.4%)	17 (7.3%)
No probiotic	109 (99.1%)	32 (94.1%)	59 (96.7%)	126 (61.5%)	55 (78.6%)	202 (87.1%)