Study says pumped breast milk has higher levels of harmful bacteria than nursing

For new mums who have to get back to work, the ability to pump breast milk and store this 'liquid gold' for their babies is a godsend. Yet, as mums, we can't help but wonder about breastfeeding vs pumping pros and cons. Are there any differences between pumped breast milk and the milk obtained from direct latching?

Now, a new study says that pumped breast milk has higher levels of potentially harmful bacteria than milk from mums who breastfed directly.

Breastfeeding vs pumping pros and cons: New study shows difference in bacteria levels

The study, published on February 13, 2019 in the journal Cell Host and Microbe, looked at 393 mother-and-infant pairs enrolled in the long-term Canadian Healthy Infant Longitudinal Development birth cohort study, known as the CHILD study.

Here are some very interesting findings from the study:

• Breast milk DOES contain some bacteria, and is not sterile. 
• According to the study, pumped breast milk had lower levels of good bacteria, and higher levels of (potentially) harmful bacteria when compared to milk from direct latching mums.
• The authors of the study stress that the findings do not imply that pumped milk is bad. It means that more research is needed to find out the reasons for this difference in bacteria levels.

Co-author of the study, Dr. Meghan Azad, told the INSIDER that pumped milk was found to have lower levels of bifidobacteria, which is considered to be a good and helpful bacteria, and is commonly found in the infant gut.

Regarding the greater levels of harmful pathogens, she clarified, "These are microbes that in certain contexts could possibly lead to infection, but this depends on other factors like what other bacteria are present, and whether the individual is immunocompromised."

She stressed that it did not mean that your baby would surely fall sick after drinking pumped breast milk.

"The study does not show that pumped milk is bad. It's not that straightforward. But it is an interesting finding that deserves further investigation", Azad told INSIDER.

"Breast milk is beneficial for many reasons, and for some moms, pumping might be the only way they can provide breast milk to their babies for a variety of reasons. So we certainly don't want to discourage pumping, but rather raise the question of what does this mean and what further research needs to be done.", she adds.

Why is there a difference in bacteria levels?

As to why exactly there is a difference in bacteria levels between direct latching and pumped milk, Azad feels that more research is needed to ascertain the exact causes.

"This might involve new recommendations about bottle feeding, cleaning breast pumps, or storing pumped milk...", she says.

According to these researchers, one reason for the change might be because pumping milk changed the milk's composition. After pumping, perhaps certain bioactive elements in the milk might have degraded, or it might be the pump itself which had introduced new elements.

As Azad says, "These are all things that we'll learn by doing the research."

Meanwhile, here are some basic do's and don'ts when it comes to pumping and storing milk:

• Before expressing or handling breast milk, wash your hands with soap and water.
• Breast pump parts, bottles and the area where you will be pumping must be clean.
• Store the expressed milk in a clean, capped glass or hard plastic, BPA-free container. You can also use special plastic bags designed for milk collection and storage.

• Don't store breast milk in disposable bottle liners or plastic bags designed for general household use.
• Using waterproof labels and ink, label each container with the date you expressed the breast milk.
• Place the containers in the back of the refrigerator or freezer, where the temperature is the coolest. If you don't have access to a refrigerator or freezer, store the milk temporarily in an insulated cooler.
• Freshly expressed breast milk can be kept at room temperature for up to six hours. It can be stored in an insulated cooler with ice packs for up to one day. It can be stored in the back of the refrigerator for up to five days in clean conditions. 

Freshly expressed breast milk can be stored in the back of a deep freezer for up to 12 months. Research suggests though, that the longer you store breast milk, even if it is in the refrigerator or in the freezer, the greater is the loss of vitamin C in the milk. 

Also READ: Cleaning your breast pump 101: New, revised guidelines