From bench to crib: translating human milk bioactive peptides into infant health interventions

Human milk (HM)-derived peptides are emerging as potent modulators of infant development, with roles that extend beyond nutrition to include immune regulation, gut maturation, and neurodevelopment. Yet, the scientific exploration of these peptides remains largely molecular in scope, disconnected from their ultimate purpose: shaping healthy infant outcomes. This review reframes bioactive milk peptides as evolutionarily adapted, function-focused molecules whose effects should be evaluated within the context of infant physiology. We examine the limitations of current discovery pipelines, highlighting the overreliance on in vitro assays, adult-derived models, and supra-physiological dosing, and argue for a translational framework grounded in developmental biology. By integrating peptidomics, infant-specific models, and systems-level validation, we describe a roadmap to identify and prioritize peptides with clinical relevance. This shift in perspective, from molecular activity to developmental impact, establishes the basis for next-generation nutrition strategies and precision therapeutics that mirror the actual biological complexity of early life.