Laura BALDOMA LLAVINES: "Potential use of microbiota-derived extracellular vesicles as a postbiotic strategy in human health"
Séminaire soutenu par la SFR B2S
Thursday 18 December, 10:30
Laura BALDOMA LLAVINES, full professor at the University of Barcelona, Gut microbiota-host interaction team, Department of Biochemistry and Physiology, University of Barcelona, Spain
Jeudi 18 décembre 2025 à 10h30, salle Ruffié batiment C IRSD et retransmission TEAMS
ABSTRACT
The intestine plays a crucial role in maintaining human health and well-being. The gut microbiota actively contributes to essential functions within the host. Clinical studies have provided insights into the influence of the gut microbiome on immunity and a wide range of diseases. Communication between the gut microbiota and the host is primarily mediated by secreted factors, particularly extracellular membrane vesicles (EVs). Scientific evidence indicates that EVs mediate microbiota functions by delivering bioactive molecules into host cells, thereby modulating cellular processes. Moreover, microbiota-derived EVs can migrate through the intestinal epithelium, cross biological barriers, enter the bloodstream, and reach distant tissues.
The high plasticity of the human microbiome provides the basis for new therapeutic strategies aimed at restoring an altered gut microbiota balance or reversing the adverse effects of dysbiosis during disease. The administration of probiotics is one such intervention. However, due to limitations in the efficacy and safety of probiotic-based therapies, the focus is gradually shifting from viable probiotic bacteria to postbiotics.
Postbiotics represent a novel health-promoting strategy based on bioactive compounds produced by probiotics or beneficial gut bacteria. They offer several advantages over live probiotics. Notably, postbiotics pose no risk of bacterial translocation, provide improved accessibility of bacterial molecules for interaction with host-specific receptors, and exhibit specific mechanisms of action that elicit targeted responses.
Microbiota-derived extracellular vesicles (EVs) fulfill the criteria and offer the benefits to be considered postbiotics. Further research on this field is essential not only for advancing our understanding of the complex microbiota–host communication network but also for establishing a solid foundation for developing new therapeutic strategies that utilize EVs from beneficial gut bacteria as postbiotics.
Studies from our group have demonstrated that EVs derived from probiotic and beneficial Escherichia coli strains exert immunomodulatory and barrier-strengthening effects in various epithelial and immune cell models. Furthermore, preclinical studies in rodent models of inflammatory bowel disease and rotavirus infection have shown that oral administration of these EVs alleviates diarrhea, clinical symptoms, and inflammation. In healthy neonatal rats, treatment with EVs from beneficial E. coli strains promotes intestinal maturation and immunity, while also modulating liver function toward an anti-inflammatory and lipid-lowering profile.
IRSD, B2S
