Mothers’ breast milk may be dramatically more important to the health of infants than previously thought. In a new study, doctors found that momma mice who breastfed their pups transferred immune cells that offered protection against infections long after breastfeeding stopped.
Doctors were aware that breastfeeding raises the immunity of an infant, but the assumption has always been that this protection is only temporary, lasting just for the time that infants are breastfed. What’s more, it was always thought that this immunity was due to antibodies transferred from the mother to neutralize bacteria and viruses.
These assumptions have been now been toppled by a new study published today in the journal Science Advances. Researchers at the University of Birmingham in the UK studied rodent offspring nursed by mothers who had a preconception helminth infection. Unexpectedly, the research team found that the protection against the worm infection was passed onto the infants by cells in the milk rather than through proteins such as antibodies. Most striking of all, these transferred cells offered protection throughout the body well into adulthood.
“This is the first demonstration that infection prior to pregnancy can transfer life-long cellular immunity to infants,” said Dr. William Horsnell, lead author of the study and a researcher at the University of Birmingham’s Institute of Microbiology.
“The work shows that exposure to an infection before pregnancy can lead to a mother transferring long term immune benefits to her offspring. This is remarkable and adds a new dimension to our understanding of how a mother can influence our health.”
In the future, the researchers would like to use this newfound knowledge to create vaccines that prevent infections. The reasoning is simple: if the immune system of mothers and would-be-mothers is primed against infectious diseases through vaccination, then babies could reap the same protective effects through breastfeeding. This new study suggests that this protection could be permanent, which is simply remarkable.
“We hope this research will lead to human investigations into how maternal exposure to pathogens prior to pregnancy can influence infant health,” added Professor Kai-Michael Toellner, of the University of Birmingham’s Institute of Immunology and Immunotherapy.