Association between polyunsaturated fatty acid intake and plasma oxylipin profiles in preterm infants: A retrospective cohort study

Objective Oxylipins, synthesized through the oxidation of polyunsaturated fatty acids (PUFAs), are bioactive downstream lipid mediators that play crucial roles in proinflammatory responses and potential cytotoxicity. Infants received PUFAs from breast milk or formula. This study aimed to describe the oxylipin profile of preterm infants receiving enteral PUFA feeding. Methods Twenty‐seven preterm infants born at 30–34 weeks of gestation were included. Weekly PUFA intake from breast milk and formula was quantified for 4 weeks, and plasma oxylipin levels were measured on postnatal days 7, 14, 21, and 28 using ultrahigh‐performance liquid chromatography mass spectroscopy. Associations between PUFA intake and oxylipins were analyzed using marginal structural models with inverse probability weighting. Results Weekly PUFA intake exhibited dynamic changes, with ω‐6 linoleic acid (LA) and alpha‐linolenic acid (ALA) peaking at Week 2, arachidonic acid (AA) increasing steadily, eicosapentaenoic acid (EPA) rising gradually, and docosahexaenoic acid (DHA) increasing sharply before plateauing. LA‐derived oxylipins remained relatively stable, with nominal positive associations that lost significance after multiple testing correction. AA‐derived oxylipins several hydroxy‐eicosatetraenoic acids exhibited strong inverse correlations with AA intake, maintaining significance after false discovery rate adjustment. DHA‐derived oxylipins, including 19,20‐ epoxy docosapentaenoic acid and several hydroxy‐docosahexaenoic acids, consistently demonstrated inverse associations with DHA intake, with all retaining significance postadjustment. Conclusion This study demonstrates that the composition of dietary PUFA intake from enteral feeding can influence the oxylipin profile in preterm infants. Negative correlations were identified between AA‐ and DHA‐derived oxylipins and their respective intakes, although the magnitude of change was notably minimal.