How to arm Caesarean babies with the gut bacteria they need

CHILDBIRTH IS MESSY. When a baby comes out, a lot else comes out with it. Some of this material is inevitable, such as the amniotic fluid that presages birth and the placenta which follows it. But a fair bit of faeces is discharged, too.From an evolutionary perspective, that seems surprising. Exposing newborns to such bacteria-laden excrement looks risky. Yet no mechanism has arisen to stop it happening. Evidence is mounting, moreover, that far from being harmful, this exposure is actually important for the development of the child’s immune system. Interaction with the multitude of microscopic organisms a baby picks up when it is born helps that system to learn friend from foe. Without it, immune disorders like allergies and type-1 diabetes may follow. Components of the gut flora are also involved in digesting certain foodstuffs containing complex carbohydrates, and an unbalance in the relevant microbial mix is implicated in obesity.