Fish oil supplementation in early infancy modulates developing infant immune responses

Abstract

Maternal fish oil supplementation during pregnancy has been associated with altered infant immune responses and a reduced risk of infant sensitization and eczema. To examine the effect of early postnatal fish oil supplementation on infant cellular immune function at 6months of age in the context of allergic disease. In a double-blind randomized controlled trial (ACTRN12606000281594), 420 infants of high atopic risk received fish oil [containing 280mg docosahexaenoic acid (DHA) and 110mg eicosapentanoic acid (EPA)] or control oil daily from birth to 6months. One hundred and twenty infants had blood collected at 6months of age. Fatty acid levels, induced cytokine responses, T cell subsets and monocyte HLA-DR expression were assessed at 6months of age. Infant allergies were assessed at 6 and 12months of age. DHA and EPA levels were significantly higher in the fish oil group and erythrocyte arachidonic acid (AA) levels were lower (all P<0.05). Infants in the fish oil group had significantly lower IL-13 responses (P=0.036) to house dust mite (HDM) and higher IFNγ (P=0.035) and TNF (P=0.017) responses to phytohaemaglutinin (PHA). Infants with relatively high DHA levels had lower Th2 responses to allergens including lower IL-13 to β-lactoglobulin (BLG) (P=0.020), and lower IL-5 to BLG (P=0.045). Postnatal fish oil supplementation increased infant n-3 polyunsaturated fatty acid (PUFA) levels and associated with lowered allergen-specific Th2 responses and elevated polyclonal Th1 responses. Our results add to existing evidence of n-3 PUFA having immunomodulatory properties that are potentially allergy-protective.