Probiotics are defined by the World Health Organization as “live microorganisms which, when administered in adequate amounts confer a health benefit on the host”. A large number of probiotic bacteria used in the food industry are members of the diverse Lactobacillaceae family and are “Generally Regarded as Safe” (GRAS). Here, we aimed at characterizing the proteome of membrane vesicles (MVs) from Lacticasibacillus casei. We notably analyzed the proteomes of vesicles purified by density gradient ultracentrifugation (pMVs) or not (MVs).