Table 3.

Associations between Having Siblings in Household and Microbiota Profiles

Microbiota and models	RRR (95% CI)	P-value
Nasal microbiota
Unadjusted model
Moraxella-dominant profile	11.6 (4.12–32.6)	<0.001
Corynebacterium/Dolosigranulum-dominant profile	Reference	-
Mixed profile	0.59 (0.14–2.51)	0.48
Adjusted model*
Moraxella-dominant profile	18.9 (5.30–67.3)	<0.001
Corynebacterium/Dolosigranulum-dominant profile	Reference	-
Mixed profile	0.62 (0.14–2.85)	0.54
Sensitivity analysis*†
Moraxella-dominant profile	6.05 (2.26–16.2)	<0.001
Corynebacterium/Dolosigranulum-dominant profile	Reference	-
Mixed profile	0.44 (0.11–1.75)	0.24
Fecal microbiota
Unadjusted model
Escherichia-dominant profile	Reference	-
Bifidobacterium-dominant profile	2.32 (0.90–5.98)	0.08
Enterobacter-dominant profile	1.26 (0.45–3.51)	0.65
Adjusted model‡
Escherichia-dominant profile	Reference	-
Bifidobacterium-dominant profile	2.90 (1.03–8.20)	0.04
Enterobacter-dominant profile	1.50 (0.44–5.12)	0.51
Sensitivity analysis†‡
Escherichia-dominant profile	Reference	-
Bifidobacterium-dominant profile	1.98 (0.94–4.15)	0.07
Enterobacter-dominant profile	1.24 (0.51–2.99)	0.64

RRR, relative risk ratio; CI, confidence interval

^*Adjusted for age, sex, maternal antibiotic use during pregnancy, maternal smoking, and history of systemic antibiotic use in infancy

^†Modeling the number of siblings as ordinal variable

^‡Adjusted for age, sex, maternal antibiotic use during pregnancy, maternal smoking, breast-feeding status, and history of systemic antibiotic use in infancy