Probiotic Delivery Systems for Inflammatory Bowel Disease: Recent Advances and Translational Challenges

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract that significantly impairs patient quality of life. Probiotics have shown therapeutic potential in modulating gut microbiota and alleviating intestinal inflammation. However, the clinical application is limited by poor viability and low bioavailability in the harsh gastrointestinal environment. These challenges have driven increasing interests in the development of effective probiotic delivery systems. This review summarized the key mechanisms of probiotics exerting beneficial effects in the human gut and systematically discussed recent advances in probiotic delivery platforms, including emulsions, nanoparticles, hydrogels, microspheres, and nanofibers. In addition, an overview of commonly used evaluation strategies was provided, focusing primarily on in vitro characterization and preclinical evidence. These assessment approaches include animal models of IBD, histological examination, imaging techniques, immunological analyses, and gut microbiota profiling. Well-designed delivery systems can effectively protect probiotics, enhance their stability and bioavailability in the gastrointestinal tract, and thereby improve their therapeutic efficacy against intestinal inflammation. Nevertheless, the clinical translation of probiotic delivery systems remains limited. Key challenges include insufficient safety evaluation, lack of standardized quality control and potency assessment, difficulties in large-scale manufacturing, and unclear regulatory pathways for live biotherapeutic products. Addressing these barriers will be essential for advancing probiotic delivery systems from experimental studies toward clinical application in IBD prevention and treatment.