Neonatal enteroids absorb extracellular vesicles from human milk-fed infant digestive fluid

Area of Science:

• Neonatal nutrition
• Extracellular vesicle biology
• Gastroenterology

Background:

• Human milk extracellular vesicles (HMEVs) show preclinical promise for intestinal health.
• The survival and uptake of HMEVs during neonatal digestion remain uncharacterized.
• This knowledge gap limits the therapeutic and nutritional applications of HMEV cargo.

Purpose of the Study:

• To develop a pipeline for isolating extracellular vesicles (EVs) from human milk and neonatal digesta.
• To test the hypothesis that HMEVs survive in vivo neonatal digestion and are internalized by intestinal epithelial cells (IECs).

Main Methods:

• EV isolation from human milk and neonatal digesta using density-gradient ultracentrifugation, filtration, and precipitation.
• EV characterization via electron microscopy, western blotting, nanoparticle tracking analysis, and microscopy.
• EV uptake studies using human neonatal enteroids.

Main Results:

• EVs were successfully isolated from both human milk and neonatal digesta (dEVs).
• Isolated EVs exhibited characteristic morphology and surface markers (CD81, CD9), with depletion of milk proteins like β-casein.
• Neonatal enteroids demonstrated rapid uptake of dEVs, partly through clathrin-mediated endocytosis.

Conclusions:

• Extracellular vesicles can be effectively isolated from neonatal digestive fluids.
• Digesta-derived EVs are absorbed by neonatal intestinal epithelial cells.
• These findings suggest a potential role for milk-derived EVs in neonatal gut health and development.