TABLE 3.

Multivariate analysis using PERMANOVA to test the variation in microbiota composition explained by each factor.

Variable	R2	P-value
Treatment (M-16V or Control)	0.238	0.009**
Gestational age (<30 or ≥ 30 weeks)	0.035	0.459
Birth weight (<1,200 or ≥1,200 g)	0.076	0.183
Discharge weight (<3,000 or ≥3,000 g)	0.036	0.444
Hospitalization period (<10 or ≥10 weeks)	0.029	0.527
Postnatal age at the fecal sampling (<16 or ≥ 16 weeks)	0.026	0.565
Corrected age at the fecal sampling (<7 or ≥7 weeks)	0.016	0.746
Fecal sampling (<5 or ≥5 weeks after discharge)	0.019	0.692
Residuals	0.524
Total	1.000

The PERMANOVA multivariate analysis was performed using a weighted UniFrac matrix.

**P < 0.01.