Soy‐based Formula Does Not Adversely Affect Immune System Development in Neonatal Piglets

Abstract

Breast‐fed infants are less susceptible to infections and allergic reactions than those fed formula, suggesting that diet may influence neonatal immune system development. The goal of the present study was two fold: 1. to determine the effect of formula feeding relative to breast‐feeding on neonatal immunity; and 2) to determine whether soy‐based formula has any adverse effects on neonatal immune system development. Piglets were breast‐fed by the sow or weaned at 2 days to a milk‐ or soy‐based formula. At PND 21, splenocytes from the sow‐fed group showed 3 to 4 fold higher T lymphocyte proliferation compared to the formula‐fed groups. The increase in T‐lymphocyte proliferation was also reflected in circulating levels of IgG and IgM in sow‐reared piglets. Notably, both formula diets showed greater NK cell cytotoxicity than the sow‐fed piglets. Our findings suggest that the neonatal innate immune system in sow‐reared piglets is functionally better developed than that in formula‐fed piglets. Comparison between soy‐ and milk‐based formulas did not show any differences in NK cell cytotoxicity, total circulating antibody levels or lymphocyte proliferation, suggesting that soy formula does not have adverse effects on neonatal immune system development. Supported by ARS CRIS#6251‐51000‐005‐03S and in part by INBRE program funded by NIH.