Effect of providing a formula supplemented with long-chain polyunsaturated fatty acids on immunity in full-term neonates

To determine the effect of feeding formula containing long-chain PUFA (LCP) on immune function, healthy term infants were randomised at age 2 weeks to either a standard term formula (Formula; it 14) or the same formula supplemented with the LCP 20: 4n-6 and 22: 6n-3 (Formula + LCP; n 16). Peripheral blood was collected at 2 and 6 weeks to measure immune cell response (the rate of [3 H]thymidine uptake and cytokine production after stimulation with phytohaemagglutinin (PHA)). Compared with cells from infants receiving only human milk (HM), the rate of [H-3]thymidine uptake in response to PHA, but not IL-2 production, was lower for Formula + LCP infants (P<0.05). Compared with HM-fed infants, Formula-fed infants (but not Formula + LCP infants) produced more TNF-alpha (unstimulated) and had a fewer CD3(+)CD44(+) cells before stimulation and fewer CD11c(+) cells post-stimulation (P<0.05). However, compared with Formula-fed infants, the Formula + LCP infants had an immune cell distribution (higher percentage CD3(+)CD44(+) and CD4(+)CD28(+) cells) and cytokine profile (lower production of TNF-alpha post-stimulation) that did not differ from HM infants. Additionally, it was found that feeding infants formula during the first 10d of life influenced immune function. These infants had a higher percentage of CD3(+), CD4(+)CD28(+), and lower percentage of CD14(+) cells and produced more TNF-alpha and interferon-gamma after PHA stimulation than HM-fed infants (P< 0.05). These results demonstrate that early diet influences both the presence of specific cell types and function of infant blood immune cells. Since many diseases have a strong immunological component, these immune changes may be of physiological importance to the developing infant.