Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 6 2025 12 13 885 892 EN Farinaz Ghaderi Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Zahra Hajebrahimi Air and Space Physiology Research Group, Aerospace Research Institute, Ministry of Science Research and Technology, Tehran, Iran Abolfazl Fateh Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran Fattah Sotoodehnejadnematalahi Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Sara Ahmadi Badi Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran Somayeh Vaezijoze Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Seyed Davar Siadat Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran 2023 12 16 2025 10 09 Background and Objectives: Tight junctions (TJs) in the gastrointestinal tract are comprised of various junctional proteins including Occludin and Zonula Occludens (ZO-1) that have a critical role in epithelial barrier function. Gut microbiota and their derived metabolites can maintain and regulate gut epithelial barrier integrity. Materials and Methods: In the present study, the effects of active, heat-inactivated, cell-free supernatant, and outer membrane vesicles (OMVs) of Akkermansia muciniphila were evaluated on the expression of occludin and ZO-1 genes in Caco-2 cell line by quantitative real-time PCR. Results: Data have shown that both forms of the active (metabolically active, growing, and dividing state), and heat inactivated (by exposure to 56°C for 20 minutes) forms of the bacteria and the cell-free supernatant could affect the expression of occludin and ZO-1 genes (P < 0.05). OMVs significantly increased the expression of the occludin gene but had no effects on the expression of ZO-1. Conclusion: Akkermansia muciniphila and its derived metabolites might have the potential to be used in the pharmaceutical and medicinal fields as probiotic, paraprobiotic and postbiotic agents to prevent metabolic and inflammatory diseases; Although, further research is needed to understand their interactions within the complex gut microbiome and to evaluate potential side effects or risks associated with their use. https://ijm.tums.ac.ir/index.php/ijm/article/view/4524 https://ijm.tums.ac.ir/index.php/ijm/article/download/4524/1835