Maternal periodontitis is associated with altered breast milk cytokines and reduced infant weight gain

Abstract Maternal periodontitis is a prevalent inflammatory condition known to impact systemic health, yet its influence on breast milk composition and infant development remains underexplored. We conducted a prospective study of 36 mother-infant pairs, assessing maternal periodontal status, breast milk cytokine profiles, and infant weight gain at one month. Here we show that mothers with periodontitis exhibit elevated TNF-α levels in mature breast milk, which inversely correlate with early infant weight gain. In vitro, exposure of human intestinal epithelial cells to milk from periodontitis-affected mothers disrupted tight junction protein organization, reduced intestinal alkaline phosphatase activity, and increased epithelial permeability; these effects were partially reversed by TNF-α neutralization. These findings suggest that maternal periodontal inflammation may alter breast milk inflammatory signaling, potentially impairing neonatal intestinal barrier function and growth. This study supports a maternal oral-milk axis linking maternal oral health to postnatal intestinal homeostasis and early infant development.