Breast Milk Contains Over 700 Bacteria

Scientists have traced the bacterial microbiota map in breast milk and discovered there are more species of bacteria than previously thought.  They discovered over 700 varieties of bacteria species in breast milk.  The exact role the microbes play is unclear but researchers believe the microbiral diversity could help the baby to digest breast milk or give the immune system a boost.

Spanish scientists used a DNA sequencing technique called pyrosequenceing, to map out the microbiome of breast milk.  Pyrosequence is a technique which uses large scale DNA sequencing determination.  Using this technique, they were able to sort out different species by looking at the variation in DNA sequences.

The first type of breast milk newborns drink is colostrum.  In some the the samples scientists found more than 700 species of these microorganisms. The first studies to document such diversity using the pyrosequencing technique on colostrum samples on the one hand, and breast milk on the other, the latter being collected after one and six months of breastfeeding.”

Scientists found that the most common bacteria were Weissella, Leuconostoc, Staphylococcus, Streptococcus and Lactococcus.  The breast milk that developed between the first and sixth month of breastfeeding was a type of bacteria found in the oral cavity.  We are not yet able to determine if these bacteria colonize the mouth of the baby or whether oral bacteria of the breast-fed baby enter the breast milk and thus change its composition.”

They also discovered a few other interesting facts.  One of these is that the milk of mothers who were overweight or gained more than the recommend amount of weight during pregnancy had less diversity of species.  They also fond that the type of labor also affects the breast milk.  Women who had a planned caesarean also had breast milk that had less diversity of species than those that had a vaginal birth.   This leads them to belived  the hormonal state of the mother during labor plays a role.

The lack of signals of physiological stress, as well as hormonal signals specific to labor, could influence the microbial composition and diversity of breast milk.”