Deciphering the Role of Postbiotics Derived from Bacillus subtilis natto on LPS-Induced Endothelial Cell Dysfunction

Background: This study aimed to assess the effects of postbiotic derived from Bacillus subtilis natto (Szendi2020) on endothelial responses under LPS-induced inflammatory stress. Methods: In human umbilical vein endothelial cells (HUVECs), inflammation was induced with 200 ng/mL LPS. Cell viability, apoptosis, and mitochondrial integrity were assessed using MTT assay, DiIC, and Sytox Green permeability assays. Intracellular ROS levels, heat shock proteins (HSPB1/Hsp27, HSPA1L/Hsp70), adhesion molecules (ICAM-1, VCAM-1), tight junction protein (Occludin), transcription regulators (NF-κB, TNFα), and proinflammatory cytokines (IL-1β, IL-6, IL-8) were quantified using qPCR and ELISA. Results: LPS exposure significantly induced apoptosis in HUVECs, as reflected by decreased metabolic activity, decreased mitochondrial membrane potential, and increased cell death (p p p p p p p p Conclusions: Our results are the first to demonstrate that postbiotics derived from Bacillus subtilis natto (Szendi2020) exert potent cytoprotective and anti-inflammatory effects in LPS-induced endothelial inflammation. By reducing ROS accumulation, preventing apoptosis, stabilizing mitochondrial and barrier integrity, modulating HSP, NF-κB, and cytokine responses. Postbiotics may be promising therapeutic candidates for alleviating endothelial inflammation and the resulting endothelial dysfunction.