At nursery, babies also build up their gut microbiota

Worried your baby might catch a virus at nursery? You’re not entirely wrong—but the surprising reality is far more upbeat. It’s true that nursery is a true hub for the exchange of microbes among infants. But far from being bad news, it’s actually a boon for their health.

A major Italian scientific study ¹, microTOUCH-baby, has recently confirmed this. For a year, researchers followed 43 infants in three public nurseries in Trento, as well as their parents, siblings, pets, and nursery staff—134 subjects in total. They analyzed the composition of each subject’s gut microbiota at regular intervals.

Babies share a lot

The results? Infants start nursery with a gut microbiota partly inherited from their mother and father and enriched by any siblings. Very quickly, babies begin to share their gut bacteria.

After one year, microorganisms received from nursery peers account for a larger portion of their gut flora than those transmitted by their own parents. Over the months, the transmission network becomes increasingly complex: certain bacterial strains spread from parent to baby, then to the baby’s playmate, then to the playmate’s parents... like an invisible game of pass-the-parcel.
 

Influencing factors

Babies who have siblings at home have a more diverse microbiota and are less likely to acquire new strains on arriving at nursery, since the space is already taken. 

Infants who receive antibiotics see their flora temporarily collapse and then rapidly replenish itself with bacteria from their peers, as if their microbiota, depleted by the treatment, were trying to rebuild itself quickly, much faster than what is observed in adults.

Other findings will reassure moms: the influence on a child’s gut microbiota of the mode of delivery (vaginal or cesarean) or the possible administration of antibiotics shortly before birth appears to have disappeared by 10 months, the median age of entry into nursery in this study.