Branched Chain Fatty Acids Are Constituents of the Normal Healthy Newborn Gastrointestinal Tract

摘要

Vernix suspended in amniotic fluid is normally swallowed by the late term fetus. We hypothesized that branched chain fatty acids (BCFA), long known to be major vernix components, would be found in meconium and that the profiles would differ systematically. Vernix and meconium were collected from term newborns and analyzed. BCFA-containing lipids constituted about 12% of vernix dry weight, and were predominantly saturated, and had 11 to 26 carbons per BCFA. In contrast, meconium BCFA had 16 to 26 carbons, and was about 1% of dry weight. Meconium BCFA were mostly in the iso configuration, whereas vernix BCFA contained dimethyl and middle chain branching, and five anteiso BCFA. The mass of BCFA entering the fetal gut as swallowed vernix particles is estimated to be 180 mg in the last month of gestation while the total mass of BCFA found in meconium is estimated to be 16 mg, thus most BCFA disappear from the fetal gut. The BCFA profiles of vernix and meconium show that BCFA are major components of normal healthy term newborn gastrointestinal tract. BCFA are candidates for agents that play a role in gut colonization and should be considered a nutritional component for the fetusewborn.