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Over 700 species of bacteria found in breast milk: What the discovery means

New discovery about bacteria in breast milk could mean better infant formula
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New research has uncovered more than 700 species of bacteria in breast milk that they say is more diverse than previously known and may help with developing healthier infant formulas. The finding is published January 4, 2013.

Newborns gain immunity from mother's breast milk. The discovery, according to Spanish scientists who conducted the study, means food scientists now have more clues about what kind of food infants need for optimal health and wellness.

Study coauthors María Carmen Collado and Alex Mira explained in a press release:


The most common bacteria isolated in colostrum of breast milk included Weissella, Leuconostoc, Staphylococcus, Streptococcus and Lactococcus.

The source of some bacteria found in breast milk between the first and sixth month of breastfeeding isn't entirely clear.


Planned Cesarean section also had an effect on the richness of bacteria in breast milk. Women who had vaginal births or unplanned C-section had a wide diversity of bacteria.

The authors thinks hormonal state of the mother at the time of birth plays a role in how rich in bacteria in her breast milk is; accounting for the finding related to planned C-section.

It might be that the type of labor affects the quality of breast milk, interfering with microorganisms needed for baby’s immune development and digestion.


Breastfeeding is known to be important for baby’s immunity and is promoted by the World Health Organization (WHO) as the best source of nutrition for infants and children that they say should start within an hour after birth.

Breast-fed babies are less likely to develop pneumonia and diarrhea because colostrum in breast milk contains antibodies that protect infants from common illnesses.

Some evidence shows adults who were breastfed as infants have higher IQs and are generally healthier than their counterparts.

The new finding, published in the American Journal of Clinical Nutrition, shows breast milk has more bacteria than previously known; over 700 species that are good for your baby. The discovery could mean better health from infancy into adulthood by understanding what hormonal and other maternal factors influence healthy bacteria in breast milk.


FECYT - Spanish Foundation for Science and Technology

January 4, 2012