Proteomic characterization of extracellular vesicles derived from lactic acid bacteria

Lactobacillus species confer health benefits by their metabolites, secreted molecules, and population numbers. Extracellular vesicles (EVs) are nano-sized particles released from cells and mediate intercellular communications. EVs-encapsulated cargos are a crucial key to decide involved biological function. However, little is known about the composition of EVs, leaving mechanisms by which Lactobacillus-derived EVs affect recipient cells remaining unresolved. This study examined the composition of EV proteins from Lactobacillus species by using liquid chromatography coupled with tandem mass spectrometry, including L. plantarum, L. fermentum, and L. gasseri. The major proteins of EVs are associated with biological processes such as catalytic activity, gluco-neogenesis, cell wall organization, and glycolytic processes. Motif enrichment analysis revealed that EVs from L. plantarum and L. fermentum contained proteins with serine-rich motif. This is the first study to report the composition and comparison of EV proteins from Lactobacillus species, providing important information of EVs in functional food products development.