Microbiome. Conceptual image of a human baby microbiome. Coloured scanning electron micrograph (SEM) of bacteria superimposed on the body of a baby.You inherited all your human DNA from your parents, but your microbiome is more complicated. Bacteria in an average human body number ten times more than human cells. Recent research has found that 30 percent of babies' gut bacteria seem to come from the mother's breast milk and that another 10 percent can be traced to skin around the mother's nipple. Bacteria in infants' faeces were more similar to the microbes from their own mothers than those from other mothers in the study, suggesting that the bacteria are transferred from mother to child through breastfeeding. When babies started eating solid food a whole new range of bacteria are found, forming the gut microbiome that persisted into adulthood.