In this study, researchers from Spain investigated whether human breast milk contains potentially probiotic lactic acid bacteria.
They isolated lactic acid bacteria from the milk, mammary areola, and breast skin of 8 healthy mothers, and from oral swabs and feces of their respective breast-fed infants.
The team selected some of the isolates and submitted them to randomly amplified polymorphic DNA (RAPD) PCR analysis. Those with identical RAPD patterns were identified by 16S rDNA sequencing.
Within each mother and newborn pair, some of the rod-shaped lactic acid bacteria had identical RAPD profiles. The team identified these as Lactobacillus gasseri.
|Breast-feeding can be a significant source of lactic acid bacteria.|
|Journal of Pediatrics|
Similarly, some coccoid lactic acid bacteria shared identical RAPD profiles. The team identified these as Enterococcus faecium.
However, the team determined that none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with the bacteria from other sources.
Dr Rocío Martín's team concluded, "Breast-feeding can be a significant source of lactic acid bacteria to the infant gut".
"Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin".