The association between polyunsaturated fatty acids in breast milk and infant eczema and its relationship with infant gut microbiota.

BACKGROUND AND OBJECTIVES: Current evidence on the relationship between breast milk fatty acids and infant eczema is limited. The present study aimed to investigate the association between polyunsaturated fatty acids (PUFAs) in breast milk and the incidence of infant eczema and its relationship with infant gut microbiota. METHODS AND STUDY DESIGN: Twenty-five infants diagnosed with eczema and fifty healthy infants born during the same period were recruited at 1 month postpartum. A follow-up was conducted on healthy infants at 6 months postpartum to determine if any new-onset eczema occurred. Breast milk and infant feces were collected at each interview. RESULTS: In the case-control study, after adjusting for confounding factors, C20:3n-3, C20:5n-3, total n-3 PUFAs, and total n-3 PUFAs/total n-6 PUFAs in breast milk were significantly inversely associated with infant eczema risk. The abundance of Clostridium and Streptococcus in the gut of infants with eczema were significantly lower than those in control group (p <0.05). C20:3n-3 and total n-3 PUFAs in breast milk were positively correlated with Clostridium abundance. In the follow-up study, the decreases of C20:3n-3 and total n-3 PUFAs in the breast milk of new-onset eczema group were greater than those of healthy group at 6 months postpartum. Moreover, the abundance change of Clostridium in infants with new-onset eczema was significantly greater than that in healthy group. CONCLUSIONS: C20:3n-3 and total n-3 PUFAs in breast milk were associated with decreased risk of infant eczema, and this association may be related to the abundance of Clostridium in infant's gut.