Cytokines in Breast Milk in Populations with Low Vs. High Risk for Atopic Diseases

Rationale:  Environmental exposure may have implications on the immunomodulatory factors contained in breast milk of varying populations.  This may have downstream effects on development of atopic disease.  We have previously shown that human milk cytokines were higher in mothers of infants with tolerance to cow’s milk when compared to cow’s milk allergic infants. The Old Order Mennonite (OOM) population has been shown to have less atopic disease than Non-Mennonites.  We hypothesize that differences may exist in the cytokine profiles in breast milk of OOM vs. non-OOM mothers.

Methods: The study used breast milk samples from 15 lactating OOM mothers and 13 non-OOM mothers.  Cytokines (IL-1b, IL-5, IL-6, IL-10, IL-17a, IL-33) were measured in processed milk samples by Milliplex kits and read on a BioRad Bioplex 200 Multiplex analyzer.

Results: Cytokines were detected in the breast milk of 15 OOM and 13 non-OOM mothers.  The expression of IL–13 was significantly increased in the OOM (median 21.50 pg/ml, range 0.00 to 319.00) when compared to non-OOM (median 10.30 pg/ml, range 7.50 to 98.00) cohort, p=0.028  (Mann Whitney).  There was a trend for higher levels of IL-10 and IL–33 in the Mennonite mothers.

Conclusions: Our preliminary data suggest that cytokine expression is higher in human milk from a population with low risk for atopic diseases.  Human milk immunomodulatory factors may serve as a surrogate for the maternal microbiome.