Effects of Fortified Formula Milk Supplementation on Neurocognitive Development and the Microbiota–Gut–Brain Axis in Preschool Children: A Cluster-Randomized, Double-Blind, Controlled Trial

Fortified formula milk improved processing speed in preschoolers, a benefit associated with gut ecosystem modulation characterized by Bifidobacterium enrichment 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).