Table 3.

The effect of possible confounding factors on the gut microbiota.

Variable/Taxonomical level	Phylum	Family	Genus	Species	ASV
Gestational age	0.036 (0.11)	0.031 (0.077)	0.031 (0.080)	0.030 (0.083)	0.020 (0.083)
Delivery mode	0.024 (0.20)	0.042 (0.20)	0.041 (0.20)	0.040 (0.20)	0.045 (0.20)
Sex of the child	0.045 (0.20)	0.018 (0.20)	0.018 (0.20)	0.022 (0.20)	0.020 (0.20)

The R2 values that describe to what extent the gestational age, delivery mode, and sex of the child explain the variance in different bacterial taxonomic levels in the gut microbiota. In brackets, the p-values of the comparisons between the intervention groups made according to the study subjects’ features concerning possible confounding factors using PERMANOVA. Gestational age, delivery mode (vaginal or caesarean section), and sex of the child were not associated with the gut microbiota composition.