There is a growing body of evidence to suggest that the bacteria a baby is exposed to from its very first moments in life may affect him or her for the rest of their lives. From neural development, to gut health and psychiatric disorders, the composition of the bacteria we carry around with us has far reaching consequences.

In a vaginal birth, the baby is squeezed through the birth canal, becoming covered tip to toe in the bacteria that populate the mother’s vagina. These bacteria make their way swiftly to the baby’s gut, where they set up camp and start to multiply. In caesarean section delivery, the bacteria a baby is exposed to are those on the mother’s skin, which are massively different from those in the vagina and lacking in several important types. Similar reductions in certain bacteria are seen in adults suffering from depression.

It has been shown that the gut bacteria populations have profound effects on personality, health and cognitive development, with reductions in bacteria associated with autism, depression, schizophrenia and other mental health disorders.

The main bacteria missing from c-section babies (and babies born to mothers who have suffered high levels of stress during pregnancy) is a subtype called Lactobacillus. Mothers who are given steroids in order to mature the baby’s lungs in the event of a premature birth (a lifesaving, necessary intervention in many cases) have been shown to have much more anxious children in a study of six to ten year-olds, likely due to the destruction of the mother’s Lactobacillus as a result of the drug, as its side effects mimic stress.

So what should I do?

  • If you are pregnant, consider taking probiotics that contain Lactobacillus, especially if you are having a stressful pregnancy. Always consult your doctor first.
  • Should your baby be delivered by c-section for any reason, have a plan in place for vaginal swabbing. This is where the baby is swabbed in secretions from the mother’s vagina almost immediately after delivery, in order to ensure the bacterial population of the baby’s gut matches the mother’s gut rather than her skin.
  • Don’t panic if this article applies closely to you or your children – warm parenting has been shown in a 2010 study to help counteract the effects upon children of their mother’s stress during pregnancy, and may well help counteract the effects of reduced lactobacillus exposure at birth.
  • Read this article on how getting muddy is good for you.
  • Or read this article on How to Protect Your Child with a Healthy Microbiome.
  • If you were delivered by c-section or want to know more about how your bacteria affect your brain, check out our Gut Health page and info on prebiotics, probiotics and how to use your gut microbiome to your advantage.
  • If you are based in Victoria, Australia, you can book your baby in to see Dr Anna Brown at