Does baby influence the breastmilk immune response?

By  7 December 2022 

Image courtesy of

"I love this idea: the potential for “backwash” communication between a mum and her baby during breastfeeding.

The hypothesis is that during breastfeeding, there is a blackflow of saliva from the baby’s mouth. The saliva gets sucked into the nipple and into the milk ducts (called retrograde duct flow.)

If the baby is sick, the baby communicates information to the mum’s immune system about the infection. In response, the composition of the mum’s milk changes — there’s an increase in antibodies to help the baby fight the infection.

But what’s the evidence? 

Does “backwash” actually trigger an immune response in the mum’s milk?

Previous studies have shown that immune components in the milk can increase if the baby is ill. This suggests the baby can communicate with the mother’s immune system — informing the mother about the baby’s health.

Now a new animal study adds an important piece of the puzzle — it tracks a signal from baby saliva TO the mammary gland TO the milk.

To summarise the study very simply: The mouse study suggests saliva from the infants mouth can transmit pathogens to the mother’s mammary gland during suckling. The resulting localised infection from the “backwash” then triggers an immune response in the mother’s milk.

What does that all mean?

The scientists discovered that the enteric viruses were directly transmitted from infected mouse baby to the mum mouse via backwash during suckling.

My Take-Home Message:

Scientists don’t yet have all the answers. There are many pieces of the puzzle still missing. This was an animal study, and mouse pups are very different from human babies.

At this stage, it is still a hypothesis that saliva “backwash” triggers an immune response in the mother’s milk for human babies.

But it is a beautiful idea: a baby passes on pathogens to the mum via backwash whilst breastfeeding. This triggers a surge of made-to-order immune factors that are specific to the pathogen causing the infection. These immune factors help the baby fight the infection.

To me, this study is further evidence that breastfeeding at the breast is so much more than simply the baby getting nutrition."

Read more :

Pic : - a Qiara mum and bub!

Qiara is a family of breastmilk isolated probiotics for pregnancy, breastfeeding, infant, kid and adult. Supporting lifelong gut health with our awarded brand, most highly rated “Vitamin and Supplement” for Mum at @TellmebabyAU 2020 and 2021. Evidence-based for 7 health outcomes including : reducing mild mastitis, restore gut flora after antibiotic recovery, restoring good bacteria after csection, supporting immunity, improve good bacteria growth and supporting gastrointestinal health. Read over 2000 brand reviews and probiotic insights @Qiaraprobiotics : Buy online