Evaluation and clinical translation of nanoprobiotic delivery systems

Nanoprobiotic delivery systems have emerged as a promising strategy to improve probiotic stability, functionality, and therapeutic efficacy. In general, nanoprobiotics refer to probiotic formulations integrated with nanoscale or nanoengineered carriers to protect living microorganisms and enhance delivery efficiency. Compared with conventional formulations, these systems provide better stress resistance, improved colonization, and more controlled or targeted release, showing broad potential in functional foods, precision nutrition, and gastrointestinal disease intervention. Despite these advances, the clinical translation of nanoprobiotic delivery systems remains limited. One of the major barriers is the lack of a systematic and standardized evaluation framework that can connect material design with biological performance and translational feasibility. Current studies often focus on isolated indicators such as encapsulation efficiency or survival rate, whereas comprehensive assessment across in vitro, in vivo, and clinical levels is still insufficient and inconsistent. In this review, we propose a multilevel evaluation framework for nanoprobiotic delivery systems to support their rational development and clinical translation. Specifically, we summarize current strategies for nanoprobiotic design and then discuss key evaluation approaches, including static and dynamic in vitro digestion models, intestinal permeability and epithelial interaction studies, animal-based biodistribution and bioactivity assessment, and clinical trials with population-level follow-up. We further highlight major translational challenges, including biosafety, large-scale manufacturing, regulatory uncertainty, and long-term stability. Overall, this review aims to provide a structured framework for the standardized evaluation of nanoprobiotic delivery systems and to accelerate their translation from laboratory research to practical clinical and nutritional applications.