Table 1.

Cohort Demographics

	Probands	Siblings with IBD	Healthy siblings	Parents
N	21	6	21	42
Crohn's disease	17	5		4
Ulcerative colitis	4	1		5
Sex
Male	14	5	10	21
Female	7	1	11	21
Race/ethnicity
Caucasian	19	6	19
Jewish	13	4	15
Mixed	2	0	2
Age at diagnosis, y	10	18.4
Age at sampling, y	13.6	19.7	12.7
Crohn's disease location
Small intestine	15	5
Colon involvement	10	4
UGI involvement	6	1
Perianal disease	7	1
Colon only	2	0
IBD medications at sampling
Anti-TNF	16	3		2
Methotrexatea	10	1		0
6-MP/azathioprinea	2	0		0
Mesalamine	6	1		2
None	1	1		3
Birth order	1.7	1.3	1.9
Mode of delivery
Vaginal	16	4	15
Cesarean	5	2	6
Gestational age, wkb	0.2	−0.3	0.0
Birth weight, lb	7.4	6.8	7.0
Perinatal disease	8	2	3
Anemia	3	0	1
Preterm labor	1	2	0
Preeclampsia	1	0	0
Other	3	0	2
Antibiotics predelivery	3	1	3
Maternal age at delivery, y	33.9	32	33.4
Exclusive breastfeedingc	20	4	17
≥2 antibiotics during first year	4	1	4

NOTE. There were no statistically significant differences in metadata between children with IBD and healthy siblings.

6-MP, 6-mercaptopurine; TNF, tumor necrosis factor; UGI, upper gastrointestinal.

^aImmunomodulators (methotrexate, 6-mercaptopurine) were combined with anti–tumor necrosis factor therapy in all except 2 patients.

^bGestational age was expressed as weeks from full-term.

^cExclusive breastfeeding was for at least 4 months after birth.