Human breast milk is the optimal nutrition for infants, representing a rich source of the essential nutrients and diversity of bioactive compounds, as well as the child´s first intestinal microbiota. As the microbiota of breast milk plays a significant role in the development and health of the newborns, characterization of the antibiotic susceptibility profiles of commensal bacteria from the human milk microbiota is essential. Therefore, the present work aimed to examine the susceptibility of selected strains of commensal bacteria isolated from breast milk microbiota to different antibiotics by the disk diffusion agar method. For 25 commensal bacteria, the values of the minimum inhibitory concentration (MIC) of antibiotics were determined by the E - test. Antibiotic resistance genes were identified by the polymerase chain reaction (PCR) method. Although phenotypic methods showed that most of the antibiotics do not inhibit the growth of commensal bacteria, the amplicons that would indicate the presence of antibiotic resistance determinants were not detected by PCR. Lactobacillus strains were not susceptible to vancomycin, which is typical for bacteria of this genus, which is described as innate resistance. The genome of all Staphylococcus epidermis AF4, AF5, MB6, MB12 and RS8 and Streptococcus oralis subsp. dentisani MB5, appeared to cotain bla gene encoding the enzyme β-lactamase according to the presence of a specific band of 297 bp detected after PCR.