 The study investigates the presence of RNA in exosomes from human saliva, plasma, and breast milk, as well as their ability to be taken up by macrophages. Exosomes were purified using ultracentrifugetiphogen and filtration steps, and detected by electron microscopy and flow cytometry. RNA was detected in all three body fluids, with a portion of the detected RNA in plasma exosomes being characterized as mRNA. The study also reports for the first time the presence of RNA in breast milk exosomes. Additionally, the saliva and breast milk exosomes were found to be readily taken up by human macrophages, supporting the notion that exosomal RNA can be shuttled between cells.