Cell | 不止是抗体！母乳靠肠菌代谢物，搭建宝宝肺部免疫防线

TL;DR - A Cell study in mice identifies a maternal milk osteopontin–gut microbiome–D-3-phenyllactic acid pathway that programs infant lung immunity and improves tolerance to respiratory infections. The findings suggest possible nutritional interventions for infants who cannot be exclusively breastfed, but human efficacy remains unproven.

• Milk-derived osteopontin enriches Lactobacillaceae that convert phenylalanine into D-3-phenyllactic acid (D-PLA).
• D-PLA stimulates liver endothelial cells to express stem cell factor, expanding hematopoietic progenitors that subsequently migrate to the lungs.
• In airway epithelial cells, D-PLA activates PPARγ, inducing CCL25 and Flt3 ligand to recruit progenitors and promote dendritic-cell development.
• Early oral osteopontin supplementation reduced viral and bacterial lung-disease severity in mice and produced lasting immune benefits; equivalent intraperitoneal delivery did not.