Table 4.

Bacteria detected in the samples of breast milk and feces of the breast- and formula-fed infants and percentage of samples in which they were detected

		Feces
Microorganism	Milk	Breast-fed infants	Formula-fed infants	P-valuea
Staphylococcus epidermidis	100.00%	86.05%	13.33%	< 0.0001
Staphylococcus aureus	16.28%	16.28%	13.33%	NSb
Other Staphylococcus spp.	16.28%	6.98%	6.67%	NS
Enterococcus faecalis	20.93%	53.49%	100.00%	0.0011
Enterococcus faecium	NDc	2.33%	13.33%	NS
Other Enterococcus spp.	4.65%	9.30%	26.67%	NS
Streptococcus spp.	27.91%	13.95%	ND	NS
Other Gram-positive bacteria	20.93%	69.77%	33.33%	0.0130
Gram-negative bacteria	46.51%	97.62%	66.67%	0.0008

^a Statistical significance between the breast-fed group and the formula-fed group (χ² test).

^bNS, not significant (P > 0.05).

^cND, not detected.