Food Science and Agriculture: Research Highlights Vol. 10

Milk contains lipid-bilayer nanoparticles that survive several of the conditions encountered during dairy manufacture and gastrointestinal transit, and that carry microRNA, protein, lipid and glycan cargo of putative biological consequence. Interest in these milk-derived extracellular vesicles has expanded rapidly across dairy science, infant nutrition, gastroenterology and pharmaceutics, yet the literature has developed along disciplinary lines that rarely interrogate one another. This review examines the field at the point where food technology, nutritional physiology and therapeutic delivery intersect, and asks how much of the reported bioactivity is secure once analytical, dosimetric and translational limitations are taken into account. Literature was identified through structured searching of open scholarly indexes, citation tracking and verification of bibliographic records against registry and publisher sources, with critical appraisal directed at analyte definition, dose reporting, control selection and the correspondence between mechanism and outcome. Four conclusions emerge. Compositional description is comparatively secure, and conserved microRNA and lipid signatures across ruminant and human milk are reproducible. Absorption is real but quantitatively unsettled, with published estimates of oral bioavailability differing by an order of magnitude for reasons that are traceable to labelling strategy and analyte definition rather than to species or dose. Functional evidence is dominated by rodent models using preparations whose purity is seldom demonstrated, and the few controlled human observations show measurable postprandial changes in circulating microRNA without accompanying physiological effect. Processing effects are directional and reasonably consistent, although quantitative comparisons across studies are compromised by inconsistent normalisation. Reports that oral administration accelerated metastasis in murine models, and the absence of registered clinical trials, indicate that enthusiasm for functional dairy applications has advanced further than the safety and dosimetry evidence supporting it. Priorities include purity-controlled preparations, standardised dose expression, and human studies with physiological rather than molecular endpoints.