Researchers say so-called "good bacteria" flow from the mother's gut to her newborn through breast milk, helping to establish good digestive health and the foundation of early immunity.  They say it is yet another reason "breast is best."

The researchers, led by Professor Christophe Lacroix at the Institute for Food, Nutrition and Health in Zurich, Switzerland, found the same strains of Bifidobacterium breve and several types of Clostridium bacteria in breast milk and in maternal and neonatal feces.  Experts believe these "good bacteria" may play a role in establishing a nutritional balance in the baby's colon and preventing intestinal disorders.

Lacroix says it's unclear how the beneficial microbes make their way from the mother's gut to her breast milk, but researchers used a variety of laboratory techniques to confirm that the strains of bacteria in newborns are the same ones as in their mothers.

Lacroix calls the discovery "exciting," saying future research will focus on discovering the exact mechanism of microbes transfer.  Swiss researchers will also try to identify which "good" bacterial strains can be added to infant formula as probiotics to establish immunity and good digestion in newborns.  

An article on the transfer of the gut bacteria is published in the current issue of the journal Environmental Microbiology.