Partially hydrolyzed formula with high sn-2 palmitic acid on eosinophils and outcomes in preterm infants: PRIOR secondary analysis

Background: Preterm infants, with immature immune systems, are susceptible to type 2 inflammation, characterized by eosinophil recruitment, exacerbating intestinal and respiratory inflammation. Breastfeeding mitigates inflammation via sn-2 palmitic acid and immunomodulatory factors (e.g., IL-10), but formula feeding is often necessary due to clinical constraints. High sn-2 palmitic acid partially hydrolyzed formula (HPF) may reduce eosinophil-related inflammation by lowering protein immunogenicity, yet evidence is limited. Methods: This secondary analysis of the ongoing PRIOR parallel-group randomized controlled trial (ChiCTR2400093296) (evaluating formula safety and growth-related outcomes) included 90 preterm infants (gestational age