P2.31. NEUROPROTECTIVE POTENTIAL OF BIFIDOBACTERIUM ANIMALIS CCDM 366 AND ITS BEVS: IMPACT ON THE BLOOD-BRAIN BARRIER FUNCTION.
Agnieszka Zabłocka1, Dominika Kozakiewicz1, Natalia Małek2, Dominika Jakubczyk1, Józefa Macała1, Sabina Górska1
1 Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Laboratory of Microbiome Immunobiology, 53-114, Wroclaw, Poland
2 Wroclaw University of Science and Technology, Department of Chemical Biology and Bioimaging, Faculty of Chemistry, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
INTRODUCTION: With age, the microbial balance in the gut becomes disturbed, contributing to systemic inflammation. Pro-inflammatory factors that reach the bloodstream can damage the integrity and function of the blood-brain barrier (BBB), causing inflammation in the central nervous system. This can result in neuronal damage and progressive decline in cognitive function (CF). While the role of gut microbiota in the gut-brain axis is increasingly recognised, the exact contribution of commensal bacteria and their secreted components remains unclear.
AIM(S): To characterise the bacterial extracellular vesicles (BEVs) produced by the commensal bacterium Bifidobacterium animalis subsp. animalis CCDM 366 (Ba366), and to investigate whether Ba366 and its BEVs have a protective effect on the BBB.
METHOD(S): Ba366 was obtained from the Laktoflora Culture Collection (Milcom, Tábor, Czech Republic). Human brain microvascular endothelial cells (HBEC-5i, ATCC) were used as an in vitro BBB model. Cell viability and proliferation were assessed using the Incucyte S3 live-cell analysis platform. Tight junction (TJ) protein expression was evaluated via Western blotting. Cytokine secretion (IL-1β, TNF-α IL-6) was measured using ELISA
RESULTS: Both Ba366 and its BEVs were non-toxic to HBEC-5i cells and could modulate their proliferation. Western blot analysis revealed significant changes in TJ protein expression, suggesting an influence on BBB permeability. ELISA results showed that Ba366/BEVs selectively stimulated IL-1β secretion, while no significant effect was observed for TNF-α or IL-6.
CONCLUSIONS: Ba366 and its BEVs can modulate BBB cell function by regulating TJ protein expression and selectively producing cytokine secretion. These findings suggest their potential role in maintaining or restoring BBB integrity, particularly under inflammatory conditions.
FINANCIAL SUPPORT: This work was partially supported by the Biocodex Microbiota Foundation.