Human breast milk regulates a baby's mix of microbes, or microbiome , during the infant's first year of life. This in turn lowers the child's risk of developing asthma, a new study shows. Led by researchers at NYU Langone Health and the University of Manitoba, the study results showed that breastfeeding beyond three months supports the gradual maturation of the microbiome in the infant's digestive system and nasal cavity, the upper part of the respiratory tract.
Conversely, stopping breastfeeding earlier than three months disrupts the paced development of the microbiome and was linked to a higher risk of preschool asthma. Some components in breast milk, such as complex sugars called human milk oligosaccharides, can only be broken down with the help of certain microbes. This provides a competitive advantage to microbes capable of digesting these sugars.
By contrast, infants who are weaned earlier than three months from breast milk and who then rely solely on formula feeding, become home to a different set of microbes -; ones that will help the infant to digest the components in formula. While many of these microbes that thrive on formula do eventually end up in all babies, the researchers showed that their early arrival is linked to an increased risk of asthma. Just as a pacemaker regulates the rhythm of the heart, breastfeeding and human milk set the pace and sequence for microbial colonization in the infant's gut and nasal cavity, ensuring that this process occurs in an orde.