Background: Allergy is a major health burden waiting for preventive solutions. Human milk is beneficial for infant growth and infectious disease prevention but its role in decreasing allergy risk is controversial. Defining which maternal environment and diet increases anti-allergenic properties of breastmilk composition is highly necessary.
Objective: To quantify immune modulators in human milk that may contribute to allergy prevention in offspring.
Methods: Milk composition of 100 mothers from the SYMBA randomised control trial where mothers were supplemented with prebiotics (n=46) or placebo (n=54) were analysed for cytokines (IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, IL-22, IL-33, IFN-γ, TNFα, TSLP and TGF-β1&2), IgA, IgM, IgG1-4, EGF, lactoferrin and sCD-14 using ELISA and multiplex optimised for small volumes of sample. Cluster analysis was done using R and R-Studio to estimate the heterogeneity among samples.
Results: 24 analytes were quantified with 100ul of milk sample only. Pro-allergenic cytokines (IL-6, TSLP) were found to be higher and anti-allergenic cytokines (IL-12, IgA) to be lower in this cohort as compared to published data. A great heterogeneity was observed in the levels of some compounds. Three clusters were identified, which were primarily influenced by IFN-γ, IL-4, IL-5, IL-33, IL-17, IL-10, IL-1β, IL-6 and TNFα levels of milk.
Conclusion: Human milk samples from SYMBA randomised control trial have a pro-inflammatory profile as compared to existing data. Unblinding will reveal the role of prebiotics in influencing the levels of anti-allergenic compounds in human milk. This will guide maternal interventions that increase the success of allergy prevention through breastfeeding.