Probiotics have long been recognized for their health-promoting properties, primarily through their interaction with the gut microbiota. In recent years, Next-Generation Probiotics (NGPs), including and , have gained attention due to their potential therapeutic applications. Beyond live bacteria, the concept of postbiotics, defined as non-viable bacterial components with health benefits, has emerged, with membrane vesicles (MVs) representing a promising new class. These nanosized extracellular structures, secreted by both Gram-positive and Gram-negative bacteria, are rich in bioactive molecules such as peptides, lipids, metabolites, and nucleic acids. Membrane vesicles have been shown to mediate intercellular communication, modulate immune responses, and influence gut barrier integrity. Their role in microbiota-host interactions makes them attractive candidates for novel therapeutic strategies, particularly in metabolic and inflammatory diseases. This review explores the current state of knowledge on MVs from NGPs, their functional properties, and their impact on health while also discussing future research directions and large-scale production challenges.