A study in The Journal of Allergy and Clinical Immunology highlights the powerful role breastfeeding plays in building a healthy gut microbiome in infants. Although infants cannot digest human milk oligosaccharides, these components nourish beneficial bacteria like Bifidobacterium infantis, a species that reduces inflammation and supports immune development.

Breast milk also contains secretory immunoglobulin A (SIgA), an antibody that blocks harmful bacteria and viruses from attaching to the gut lining, and reduces inflammation in infants. Higher SIgA intake in infancy leads to healthier immune patterns and may provide better protection against allergies and infections. Breast milk also includes living bacteria and other bioactive molecules that contribute to the early seeding of the gut, helping to set the stage for the infant’s future microbiome.