Human Milk MicroRNAs/Exosomes: Composition and Biological Effects

Breastmilk contains many components believed to affect short and long-term outcomes for infants.  These include bioactive proteins, complex oligosaccharides (HMOs), long-chain PUFAs, milk fat globule membranes (MFGMs), nucleotides, probiotics (microbiotics) and exosomes.  In this presentation, Bo Lönnerdal explains what exosomes are and their role, having first been identified in 2007.

He outlines new research in the US which has proven that exosomes in breastmilk can survive digestion even under infant gastrointestinal conditions.  The exosomes contain microRNAs that may affect expression of genes involved in several signaling pathways regulating cell growth/proliferation and immune function, as they may also be transferred to blood and reach other target organs such as the liver and brain.   

Exosomes/microRNAs in human milk may be another mechanism affecting early development of breastfed infants, but this field of research is very much in its infancy and more study is needed.