Multi-Strain Probiotic Lysate Attenuates TGF-β1-Induced Intestinal Fibrosis and EMT Modulating Smad, Akt, and WNT/β-Catenin Pathways

Intestinal fibrosis is a common complication of inflammatory bowel diseases (IBD), and, to date, effective and safe antifibrotic drugs are still lacking. Emerging evidence suggests that probiotics may provide novel strategies to counteract fibrotic processes. In this study, we evaluated the anti-fibrotic potential of a multi-strain probiotic formulation, OxxySlabTM, using in vitro models of intestinal fibrosis and epithelial-to-mesenchymal transition (EMT). Human intestinal fibroblasts (CCD-18Co cell line) and epithelial cells (Caco-2 cell line, IECs) were stimulated with transforming growth factor-beta 1 (TGF-beta 1) to induce fibrotic and EMT phenotypes, respectively. Treatment with OxxySlab modulated cell proliferation and fibrosis-related markers, which we assessed through CCK-8 assay, Western blotting, and immunofluorescence. The probiotic lysate inhibited both canonical and non-canonical TGF-beta 1 signaling pathways, and it also reduced TGF-beta 1 gene expression in activated myofibroblasts, as shown by RT-qPCR. Furthermore, probiotic treatment reversed EMT features by restoring epithelial markers and downregulating mesenchymal markers. These findings highlight the beneficial effects of the multi-strain probiotic formulation as an adjunctive therapeutic agent targeting key pathways involved in intestinal fibrosis.