Lower caprylate and acetate levels in the breast milk is associated with atopic dermatitis in infancy.

Background: Atopic dermatitis (AD) occurs in exclusively breastfed infants. As fatty acids have some immunomodulatory effect, we aimed to investigate the influence of fatty acid compositions in breast milk (BM) on the development of AD in exclusively breastfed infants.

Methods: We enrolled two- to four-month-old exclusively breastfed infants. The objective SCORing Atopic Dermatitis (objSCORAD) was evaluated. The lipid layer of BM was analyzed by gas chromatography for fatty acid levels. Medical charts were reviewed.

Results: Forty-seven AD infants and 47 healthy controls were enrolled. The objSCORAD was 20.5 ± 1.7 (shown as mean ± SEM) in the AD group. The age, sex, parental atopy history, and nutrient intake of mothers were not significantly different between two groups. The palmitate and monounsaturated fatty acid (MUFA) levels in BM positively correlated with objSCORAD, while caprylate, acetate, and short-chain fatty acid (SCFA) levels negatively correlated with objSCORAD (p = .031, .019, .039, .013, .022, respectively). However, the butyrate levels in BM were not significantly different. The caprylate and acetate levels in BM were significantly associated with the presence of infantile AD (p = .021 and .015, respectively) after adjusting for age, sex, parental allergy history, MUFA, palmitate, and SCFA levels in BM. ObjSCORAD in infancy was significantly associated with persistent AD (p = .026) after adjusting for age, sex, parental atopy history, caprylate, palmitate, MUFA, acetate, and SCFA levels in BM.

Conclusion: Caprylate and acetate levels in BM for exclusively breastfed infants were negatively associated with objSCORAD. Lower caprylate and acetate in BM might be the risk factors for infantile AD, while butyrate in BM was not associated with infantile AD.