Table 5.

Univariate linear associations between sequencing quality indicators and maternal and infant characteristics, milk collection timing, and infant feeding characteristics.

	Proportion of rRNA		Proportion unmapped reads
	β (95% CI)	P	β (95% CI)	P
Maternal and infant characteristics
Mother age (years)	-0.0003 (-0.002, 0.001)	0.72	0.004 (-0.0002, 0.007)	0.06
Socioeconomic status	-0.0004 (-0.001, 0.0004)	0.31	0.0001 (-0.002, 0.002)	0.88
Pre-pregnancy BMI (kg/m2)	0.0008 (-0.001, 0.003)	0.42	-0.004 (-0.008, -0.003	0.04
Maternal BMI (kg/m2)	0.0003 (-0.002, 0.002)	0.78	-0.004 (-0.009, -0.00002)	0.049
Infant sex	0.02 (-0.003, 0.04)	0.10	-0.02 (-0.07, 0.02)	0.30
Mode of delivery	0.003 (-0.02, 0.03)	0.77	-0.02 (-0.07, 0.03)	0.46
Days postpartum	0.0003 (-0.003, 0.003)	0.82	-0.0003 (-0.007, 0.006)	0.92
Gestational age
Breast milk collection timing
Season (ref = cold)	0.01 (-0.006, 0.03)	0.16	-0.01 (-0.05, 0.03)	0.65
Breast milk collection time (hours past midnight)	-0.003 (-0.01, 0.003)	0.30	-0.02 (-0.03, -0.003)	0.02
Infant feeding characteristics
Predominantly breastfed	-0.003 (-0.02, 0.02)	0.73	0.02 (-0.02, 0.01)	0.27
Breastfeedings per day	-0.002 (-0.006, 0.002)	0.29	0.002 (-0.007, 0.01)	0.67

Beta coefficients and 95% confidence intervals (CI) from univariate linear regression analysis used to examine the associations between sequencing quality indicators and maternal and infant characteristics, milk collection timing, and infant feeding characteristics. P-values in bold denote statistical significance for P or P_FDR < 0.05.