What if the mother’s womb were much more than just a nest for the unborn baby? Scientists have just discovered a surprising mechanism: the mother’s gut microbiota, and more specifically an immunological molecule, could influence the child’s neurological development. This discovery reignites the search for an understanding of autism spectrum disorders.
In recent years, science has continually rediscovered the importance of our gut. This veritable “second brain” is home to trillions of bacteria that constantly communicate with our bodies. Today, a new study takes this a step further, focusing on a key period: pregnancy . What if the expectant mother’s gut microbiota could, from the very beginning, influence her child’s brain development?
Deciphering: how an inflammatory molecule acts in the fetal brain.
Published in The Journal of Immunology , this research focuses on a molecule well-known to immunologists: interleukin-17a (IL-17a). Generally associated with conditions such
as psoriasis or multiple sclerosis, it could also have an impact on neurological development before birth. To test this, scientists worked with pregnant mice. The result: those whose gut microbiota was more likely to trigger an inflammatory response (and, therefore, to produce more IL-17a) gave birth to offspring whose behavior resembled that observed in autism: stereotypies , social avoidance, etc. This surprising indication suggests that the mother’s bacterial environment could play a significant role long before birth.
Fecal transplant: a revolutionary experiment.
To confirm this hypothesis, the researchers took the experiment even further. They performed a fecal transplant between mice, thus transferring the gut microbiota from one individual to another. The result was unequivocal: the recipient mice, which inherited a pro-inflammatory gut microbiota, developed autism-like behaviors. This suggests that the maternal gut microbiota, by modifying the infant ‘s immune system , could influence brain development. This hypothesis is still
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in the exploratory phase, but it sheds new light on mechanisms that have long remained unknown.
