Park_2025_Int.J.Mol.Sci_26_11732

Extracellular vesicles (EVs) derived from probiotic bacteria have recently emerged as postbiotic mediators that regulate host cellular responses. This study investigated the effects of EVs from Lactobacillus rhamnosus BS-Pro-08, isolated from kefir grains (Lacto EV), on adipocyte differentiation and lipid metabolism. Lacto EV treatment markedly suppressed the differentiation of 3T3-L1 preadipocytes into mature adipocytes, as reflected by reduced lipid accumulation and decreased expression of the adipogenic transcription factors peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding protein alpha (C/EBPalpha). This inhibitory effect was most pronounced at the early stage of adipogenesis. In mature adipocytes, Lacto EV enhanced lipolysis in a dose-dependent manner, accompanied by increased glycerol release and total lipase activity. Interestingly, these lipolytic responses occurred despite reduced protein levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), suggesting that Lacto EVs may mediate an EV-enhanced lipolysis that is not fully explained by canonical ATGL/HSL signaling. Collectively, these findings demonstrate that Lacto EV modulates both adipogenic and lipolytic processes in vitro, providing insight into the metabolic actions of probiotic-derived vesicles.