Bacterial Community of Breast Milk in Breastfeeding Women Using Culture-Dependent and Culture-Independent Approaches

This study aimed to analyze bacterial communities in breast milk obtained from five breastfeeding women. Culture-dependent and culture-independent methods were used to analyze microbial communities. Total bacterial count of breast milk determined using plate count agar ranged from 3.3 x 104 +/- 3.5 x 102 colony forming unit (CFU)/g to 1.7 x 105 +/- 3.5 x 103 CFU/g, with a pH between 6.4 and 6.8. Only three species, Leuconostoc citreum (17 out of 160 strains; 10.63%), Staphylococcus epidermidis (118 strains; 73.75%), and Staphylococcus lugdunensis (25 strains; 15.63%), belong to the phylum Bacillota were detected by culture-dependent analysis. Microbial communities analyzed via pyrosequencing revealed greater diversity compared to the culture-dependent analysis. At the phylum level, Bacillota accounted for 60.9% of the microbial community. At the genus level, Staphylococcus (24.57%), Streptococcus (22.93%), and Methylobacterium (8.76%) were dominant genera. While pyrosequencing demonstrated greater microbial diversity than the agar plate culture method, identified microbes might lack information or include many unculturable microbes. Most of all, considering the low total bacterial count averaging 7.2 x 104 CFU/g, further research is needed to determine the significance of microbial presence in breast milk.