Healthy Kids
Healthy Kids
Breastfeeding Shapes a Baby’s Gut and Immune Health
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Breastfeeding plays a powerful role in building a healthy gut microbiome in infants according to a study in The Journal of Allergy and Clinical Immunology. The gut microbiome is a community of microorganisms that begins to form at birth and has lasting effects on digestion, immunity, and disease resistance. Breast milk not only provides nutrients for growth but also delivers complex ingredients that influence the bacteria that thrive in a baby’s gut.
One of the most important ingredients in human milk is human milk oligosaccharides (HMOs). These special sugars are not digestible by the infant but serve as food for beneficial bacteria like Bifidobacterium infantis. This species is especially adapted to use HMOs and helps reduce inflammation and support immune development. This shows a deep evolutionary relationship between mothers, milk, and microbes.
Breast milk also contains secretory IgA (SIgA), an antibody (or fighter within the immune system), that helps protect infants from infections and guides the growth of helpful microbes. SIgA blocks harmful bacteria and viruses from attaching to the gut lining and helps reduce inflammation by shaping how the infant’s immune system responds. Infants who receive more SIgA early in life show healthier immune patterns and may be better protected against allergies and infections.
In addition to these components, breast milk contains living bacteria and other bioactive molecules. These may come from the skin, mouth, or gut and contribute to the early seeding of the infant gut. Although the number of bacteria passed through breast milk is small, they may help set the stage for the infant’s future microbiome.
While we now understand how some milk components like HMOs and SIgA influence infant gut and immune development, many questions remain. Scientists are working to uncover how other breast milk ingredients work together and how changes in breast milk over time affect health. They are also exploring how viruses and other microbes in the infant gut may interact with bacteria and the immune system.
