BACKGROUND/OBJECTIVES: The preschool period is critical for neurodevelopment, yet evidence investigating fortified formula's effect and potential microbiota-gut-brain axis mechanisms in this age group is limited. To evaluate fortified formula milk's effect on neurodevelopment and explore potential microbiota-gut-brain axis mechanisms in preschool children.
METHODS: In this 9-month cluster-randomized, double-blind, controlled trial, 120 healthy children aged 3-6 years from four kindergarten classes were stratified by grade and randomly allocated (1:1) to receive either multi-nutrient fortified formula (intervention,= 60) or standard control milk (= 60). Neurocognitive function was assessed using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Safety was evaluated through anthropometry and blood biochemistry. Gut microbiota (16S rRNA sequencing) and fecal metabolomes (untargeted LC-MS) were analyzed at baseline and 9 months. n n
RESULTS: The intention-to-treat (ITT) analysis showed no significant difference in Full Scale Intelligence Quotient (adjusted mean difference: 1.05 points; 95% CI: -1.42, 3.52;= 0.400). However, the intervention group significantly improved the Processing Speed Index (adjusted mean difference: 5.91 points; 95% CI: 1.88, 9.93;= 0.004), increased gut microbial alpha diversity (Shannon index) andabundance. Metabolomic analysis revealed elevated fecal 2-hydroxybutyric acid (2-HB), a marker of propanoate metabolism. Increases in bothand 2-HB levels showed a positive association with PSI improvement (both< 0.05). All children maintained normal growth and safety parameters. p p Bifidobacterium Bifidobacterium p
CONCLUSIONS: Fortified formula milk improved processing speed in preschoolers, a benefit associated with gut ecosystem modulation characterized byenrichment and upregulated microbial propanoate metabolism. These results offer preliminary evidence for the role of the microbiota-gut-brain axis in nutritional cognitive programming during early childhood. (Clinical Trial Registry: ChiCTR2400084211). Bifidobacterium
Gut-Brain Axis