Our babies' first invaders

When a baby is still in his mummy’s tummy, his gut is free of germs (although this is now a debatable matter). As soon as he is born - the natural way or by C-section - baby will encounter millions of germs that will be the firsts to colonize this brand new body.

As we are learning now, the type of microbes that first set foot in our baby’s gut will determine a multitude of factors with long-term consequences.

If we think about the way a baby is born naturally, the first microbes he will encounter will be those of his mum’s vagina and poo. You may think how gross it is that baby’s head first contact is with poo but rest assured it is all in the Plan:



When you look at a mum-to-be’s microbiota, changes in her gut flora already occurred during her pregnancy: what happens is that Mum is preparing to offer her future baby with the best and most useful microbial starter pack with which he can establish his own colonies. This process of microbial shifts even includes mum's gut microbiota ending up in her vagina for a swift delivery to baby when he’s out through the birth canal.

Mum-to-be’s microbiota is changing during pregnancy to provide baby with the best microbial start - Do you want to tweet this?

When baby is ready and contractions finally start, mum’s gut and vagina are travelling 'down' to populate the birth canal with a specific collection of germs that is specifically designed for baby, e.g. lactic acid bacteria such as Lactobacillus and Prevotella are specialists in educating a baby’s digestive system and immunity:

They will become the first armed police of the gut - thanks to the natural antibiotics they produce - and will fight off other invaders that might not have been invited such as Streptoccocus, Pseudomonas, C difficile – all nasties for such a young and delicate age.

These lactic acid bacteria are also perfect because they help baby digest milk by converting the milk sugar lactose into lactic acid, creating energy. Most of this lactose will have been digested by our small intestine beforehand but the leftovers that are passed on to our large intestine will be taken care of by gut bacteria.

As baby develops, he will acquire more diverse germs as his own diet diversified.
It stands to wonder then, what happens to babies in the Western world who are born by C-section (available soon)?

Although in some cases it is in mum’s and baby’s best interest to adopt these modern techniques, we may wonder soon if some countries where being born by C-section is the norm don’t overdo it at the unbeknownst detrimental effect on our babies...

Do you think modern societies are too sterile

when it comes to baby birth? 

Would you like to share your thoughts? Please leave me a comment, I’d love to read them.

All this amazing information was found in this scientific review: Belkaid Y, and Hand TW. Cell 2014; 157: 121-41.