Abstract:Outer membrane vesicles (OMVs) are spherical structures secreted by Gram-negative bacteria, with diameters of 10-250 nm. OMVs have gradually been recognized as a novel secretion system capable of transporting various substances such as lipids, proteins, nucleic acids, cytotoxins, and signaling molecules. OMVs possess a range of biological functions, including inter-bacterial communication, transmission of pathogenic factors, resistance to adverse external environments, and modulation of immune responses. Due to the distinct biological characteristics of OMVs, the antibiotic resistance transmission mediated by bacterial OMVs, as well as the potential applications of OMVs, has garnered increasing attention in recent years. This paper reviews the origins and substance delivery functions of bacterial OMVs and the protective effects of OMVs on the bacteria exposed to antibiotics and in adverse environments. Furthermore, this paper summarizes the potential applications of bacterial OMVs in the treatment of diseases, aiming to enrich the knowledge about bacterial OMVs.