07/20/2025
Your milk contains phagocytes, white blood cells that pass through your baby’s gut wall and patrol around your baby’s bloodstream.
There, they detect, engulf and destroy harmful micro-organisms; bacteria, viruses, fungi, and foreign materials that aren’t supposed to be there, like dust particles or pigments, and also cancer cells, though these cells can sometimes adapt and evade detection.
Phagocytes also remove dead or dying cells that can cause inflammation and disease.
Once phagocytes have destroyed the harmful micro-organism, they retain harmless fragments of this pathogen on their surface, allowing another type of protective cell - the T cells - in your baby’s immune system to learn from them.
T cells learn to recognise the pathogens, developing your baby’s long term immunity.
It’s like a whole military operation going on, whilst we sit and feed our children like nothing appears to be happening at all.
We are all born with immature immune systems. Your milk not only helps your baby’s immune system to develop in a healthy way, it also helps to protect your baby from illness while this happens.
Our immune systems take around 6 years to fully develop, which is thought to be one of the reasons that natural term breastfeeding (allowing a child to stop breastfeeding in their own time without interrupting or replacing breastmilk) extends from anywhere between around 2 and 7 years old.
Some extra geekiness: The word phagocyte comes from the Greek ‘phagein’, ‘to eat’ or ‘devour’, and ‘-cyte’, a word-forming element used in modern science to mean "of a cell," from the Greek word kytos, meaning ‘a hollow’, ‘receptacle’, ‘basket’.
So Mama, are you remarkable, or are you really, really remarkable?
More science (ie information bout how incredible you are), support, and references at https://human-milk.com/pages/science-of-breastmilk
