Human Milk Bioactive Compounds and Psychomotor Outcomes in Infants and Children: A Systematic Review

Human milk (HM) provides nutrients and bioactive compounds (BCs) essential for healthy child development. This systematic review aimed to evaluate the short- and long-term effects of individual groups of BCs on psychomotor outcomes, including motor, cognitive, language, and executive functions. A comprehensive literature search was conducted in MEDLINE (PubMed), Scopus, Web of Science, and Embase in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligibility was defined using the PECOTS framework, focusing on healthy, term, breastfed children with follow-up up to 18 years. Study quality was assessed with the Joanna Briggs Institute (JBI) tool and Cochrane Risk of Bias (RoB 2) tools. Eighteen studies met the inclusion criteria. The most consistent evidence was for polyunsaturated fatty acids (PUFAs), particularly n-3 PUFAs, which were generally associated with favorable psychomotor outcomes throughout infancy and later childhood. In contrast, higher levels of n-6 PUFAs showed less consistent or potentially unfavorable associations. Among HM oligosaccharides, fucosylated HMOs were consistently associated with improved cognitive and language-related outcomes, whereas evidence for other HMO groups was limited and heterogeneous. Findings related to proteins, phospholipids, sphingolipids, and carotenoids were inconsistent. HM BCs, particularly n-3 PUFAs and fucosylated HMOs, may support psychomotor development in infancy, preschool age, and school age. However, the overall evidence remains heterogeneous. Further research using standardized methodologies is required to elucidate long-term effects and underlying mechanisms.