Breast-feeding is back. When it comes to early establishment of gut and immune health for babies, 'breast is best' according to a new study of how 'good' bacteria arrive in babies' digestive systems.

How babies acquire a population of good bacteria can also help to develop formula milk that more closely mimics nature.

 The researchers found the same strains of Bifidobacterium breve and several types of Clostridium bacteria, which are important for colonic health, in breast milk, and maternal and/or neonatal faeces. Strains found in breast milk may be involved in establishing a critical nutritional balance in the baby's gut and may be important to prevent intestinal disorders.

Professor Christophe Lacroix at the Institute for Food, Nutrition and Health, ETH-Zurich, Switzerland, said,"We are excited to find out that bacteria can actually travel from the mother's gut to her breast milk. A healthy community of bacteria in the gut of both mother and baby is really important for baby's gut health and immune system development.

"We're not sure of the route the bacteria take from gut to breast milk but, we have used culture, isolation, sequencing and fingerprinting methods to confirm that they are definitely the same strains."

Future research will hopefully complete the picture of how bacteria are transferred from mother to neonate. With a more thorough knowledge, we can decide which bacterial species will be most important as probiotics in formula. But until then, for neonates at least, the old adage is true, breast is best.

Published in Environmental Microbiology, no DOI yet.