Whenever I give a talk at a conference, or during a Q&A after a film screening of Microbirth, or at a book event, or posted as a comment in the discussion about the free webinar, the same questions tend to crop up. These questions are answered in much more detail within the 9 hour course, but I thought I would provide quick answers in a series of FAQ themed blog-posts.

Frequently Asked Question

Donor Breast Milk

The question is often asked like this: "Does donor breast milk impact the infant microbiome?"

Or like this: "Is another mother's breast milk "better" for the infant microbiome than formula milk?"

My Answer:

As explained within the full 9 hour course, in a nutshell, the microbial components of donor breast milk might not exactly match the microbial components of the biological mother's own breast milk.

For example, the human milk oligosaccharides (special sugars) in donor breast milk might not be exactly the same as the oligosaccharides found in the biological mother's own breast milk.

This could mean that the vaginal and gut bacteria newly arrived in the infant gut (transferred from the mother during vaginal birth) might not receive the exact type of oligosaccharides that are perfectly matched to optimally feed them. This could have consequences for the optimal development of the infant immune system.

But we don't know for sure what the long-term consequences of this might be because there haven't been that many studies published looking specifically at the infant microbiome and donor breast milk.

Image Credit: By ParentingPatch (Own work) CC BY-SA 3.0

There have been quite a few articles about breastfeeding which include discussion of donor breast milk. For example, in an open access article called "Benefits of Human Milk in Preterm Infant Feeding" by Bertino et al., (2012) published in the Journal of Pediatric and Neonatal Individualized Medicine, the authors talk about donor breast milk as the "second best alternative" to a mother breastfeeding her own child.

"When mother milk is unavailable or in short supply, donor milk (DM) represents the second best alternative and although some nutritional elements are inactivated by the pasteurization process, it still has documented advantages compared to formula. The demonstrated benefits of human milk (HM) highlight the importance of health care professional education in the support of breastfeeding."

What about pasteurising donor breast milk?

In most donor milk banks, the donated breast milk is pasteurised. This is a process where the human milk is heated to kill pathogens (bad bacteria).

For example, the North American human milk banks that form the non-profit HMBANA (Human Milk Banking Association of North America) pasteurise and test all donated human milk. (According to their website, to date HMBANA have dispensed 3.77 million ounces!!!) The whole pasteurisation process within HMBANA is shown on this link.

However, pasteurisation does impact the bacteria and other bioactive components of donor breast milk. According to a paper called "Personalization of the Microbiota of Donor Human Milk with Mother's Own Milk" by Cacho et al., (2017) published in Frontiers in Microbiology, 99% of bacteria are killed.

"Pasteurization of donor breast milk kills 99% of bacteria and may also inactivate a large proportion of the bioactive components. Since donor breast milk is pooled and pasteurized, it lacks the unique live maternal milk microbiome, which may be of benefit to the infant"

A possible solution?

But all is not lost with pasteurisation. Or at least, it might not be.

The 2017 Cacho et al., paper suggests that adding a small amount of the biological mother's own breast milk to pasteurised donor breast milk can restore the microbial components.

"In summary, we have shown that each mother has a unique milk microbiota and that the live microbiome in donor breast milk can be restored with these unique bacteria using small amounts of mother's own milk".

If the results are replicated in a larger study, this technique of adding a small amount of the biological mother's breast milk to donor milk could be a viable way to restore the microbial components which potentially could benefit the infant.

With more research, hopefully it won't be too long before we have more definite answers about the infant microbiome and donor breast milk.

In the meantime, if you want more evidence-based information on the infant microbiome including the microbial super power of breast milk, check out our FREE WEBINAR called "Understanding The Infant Microbiome" featuring 7 world-leading professors!

Science references:

Bertino et al., Journal of Pediatric and Neonatal Individualized Medicine 2012;1(1):19-24 doi: 10.7363/010102 http://www.jpnim.com/index.php/jpnim/article/viewF...

Cacho et al., Front. Microbiol., 03 August 2017 | doi.org/10.3389/fmicb.2017.01470 https://www.frontiersin.org/articles/10.3389/fmicb...

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