OMVs (Outer Membrane Vesicles) are nanosized vesicles with a double membrane structure secreted by Gram-negative bacteria at all stages of bacterial growth. They carry a variety of parental bacterial cell bioactive substances, which can reflect the physiological and pathological state of their parent cells. Changes in the external environment or drug-stimulated conditions such as antibiotics can also be detected in a more timely manner. The addition of glycine during bacterial culture can promote the work of bacterial efflux pumps, which in turn manifests as an increase in the secretion of OMVs. Therefore, the researchers systematically analyzed the proteomics of glycine-induced secretion of OMVs using LC-MS technology.