Breast really IS best: Mothers' milk fills a child's digestive system with essential 'good' bacteria Study found good bacteria can travel from mother's gut to her breast milk It contains protective bugs for digestive and immune system health in babies Research could be important to help prevent intestinal disorders in infants Breast is best for filling babies' digestive systems with essential 'good' bacteria, research shows. A thriving population of beneficial gut bugs is vital to an infant's digestive health and immune system development. The new research suggests that the bacteria can be transferred to a suckling baby in breast milk. Swiss scientists found identical strains of the microbe Bifidobacterium breve and several types of 'good' Clostridium in both a group of babies and the breast milk they were being fed with. Good bacteria from the milk of breast-feeding mums can protect the digestive and immune system health of her baby, say scientists The strains may help establish a critical nutritional balance in the guts of infants and could be important for preventing intestinal disorders, they believe. Study leader Professor Christophe Lacroix, from the Institute for Food, Nutrition and Health in Zurich, 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 takes from gut to breast milk but, we have used culture, isolation, sequencing and fingerprinting methods to confirm that they are definitely the same strains.' The findings are published in the latest issue of the journal Environmental Microbiology. DNA tests were carried out on the breast milk of seven healthy mothers and their exclusively breast-fed babies who were up to one month old. The scientists tested faecal samples to identify bacteria in the guts of both infants and their mothers. Breast beats the bottle again: Previous research has shown breast milk protects babies against stomach bugs, chest infections, asthma and allergies The researchers wrote: 'This study shows that gut-associated anaerobes may be vertically transferred from mother to neonate (infant) via breastfeeding. Our data supports the recently suggested hypothesis of a novel way of mother-neonate communication, in which maternal gut bacteria reach breast milk via an entero-mammary pathway to influence neonatal gut colonisation and maturation of the immune system. Japanese research published earlier this month found that breastfeeding can halve the risk of children being obese by the age of eight.