Amino acid nutrition in fetal and neonatal growth: from animal studies to clinical applications

Abstract

Studies of porcine milk composition over 18 years ago created a new direction of amino acid research. Specifically, the discovery of arginine (Arg) deficiency in sow milk led to the identification of glutamine and proline as the major substrates for Arg synthesis in piglets. Subsequent work resulted in the recognition that Arg is deficient in preterm infants with necrotizing enterocolitis and that its supplementation can ameliorate the gut disease. Further research on the ontogeny of Arg‐synthetic enzymes in the porcine intestine led to the discovery that the Arg family of amino acids is unusually abundant in allantoic fluids of swine and sheep during early gestation when placental growth is most rapid. This novel observation provided a strong basis for the effective use of Arg to improve embryonic/fetal survival and ameliorate intrauterine growth restriction in mammals (including pigs, sheep and humans) via enhancing NO‐mediated blood flow. Additional work to elucidate the underlying mechanisms led to another discovery that Arg reduces adiposity in pigs, sheep and rats. Notably, this knowledge has been translated into the use of Arg to promote white‐fat loss and improve insulin sensitivity in obese patients with type‐2 diabetes mellitus. Thus, animal models play an important role in developing new means to prevent and treat a wide array of major human diseases. Supported by NIH, USDA, AHA, and TAMU.