A study in mice shows that the probiotic Bifidobacterium breve, when taken by mothers during pregnancy, enhances fetal brain development by improving nutrient transport and growth processes. The findings suggest that altering the maternal gut microbiome with probiotics could be a non-pharmaceutical strategy to support healthy fetal growth, particularly in cases of fetal growth restriction. Further research is needed to confirm these effects in humans and explore how probiotics interact with other gut bacteria during pregnancy.