Effect of feeding a formula supplemented with long-chain polyunsaturated fatty acids for 14 weeks improves the ex vivo response to a mitogen and reduces the response to a soy protein in infants at low risk for allergy

Abstract

Background and objective: Feeding long-chain polyunsaturated fatty acids (LCP) influences immunity in adults; however, less is known about their effect during development. The aim of the study was to determine the effect of feeding LCP on immunity in healthy infants during the first 4 months of life.

Patients and methods: Formula-fed infants were randomized at <or=14 days of age to standard term formula (Formula) or formula containing LCP (Formula+LCP). Infants exclusively fed human milk (HM) were included for comparison. At 16 weeks of age, blood was collected and phenotypes, the ability to proliferate and produce cytokines (interleukin [IL]-2, IL-4, IL-6, IL-10, IL-12, interferon [IFN]-gamma, tumor necrosis factor [TNF]-alpha, TGF-beta) after incubation with phytohemaglutinin (PHA), beta-lactoglobulin, or soy protein were measured.

Results: Feeding LCP resulted in a higher than and more similar proliferation rate to PHA in HM-fed infants, possibly because of a greater TH1 type cytokine response and a higher percentage of antigen mature (CD45RO+) cells (P < 0.05). The response to beta-lactoglobulin did not differ among groups. After incubation with soy protein Formula+LCP, compared with Formula produced less IL-2 and more TNF-alpha and had a higher percentage of CD8+ and a lower percentage of CD20+ (CD20+CD54+) cells poststimulation (P < 0.05). Both formula groups produced less IL-2 after PHA, had a lower percentage of CD80+ cells, and a higher percentage of CD54+ cells after incubation with food proteins (P < 0.05).

Conclusions: Formula-fed infants, at low risk for allergy, respond differently to mitogen and food proteins ex vivo than those fed HM. Feeding LCP altered some of these differences in the direction that is hypothesized to confer immune benefits.