Various Strategies for Intelligent Intestinal Protection, Adhesion, and Survival of Probiotics

Probiotics are increasingly recognized for their ability to modulate gut microbiota and host immunity, yet their oral efficacy is severely limited by gastrointestinal barriers that compromise viability and colonization. This review summarizes recent advances in intelligent delivery systems for probiotics. These systems are designed to protect probiotics from gastrointestinal stress and enable site-specific release in the intestinal tract. We focus on four categories of stimulus-responsive platforms, namely pH-sensitive, redox-driven, enzyme-triggered, and pressure-responsive systems, detailing their design principles, material selection, and fabrication strategies. To address the challenge of sustained intestinal retention, we evaluate approaches that enhance mucosal adhesion and colonization, including biofilm-based encapsulation, single-cell coating techniques (lipid membranes, biomimetic membranes, and functional nanocoatings), and biopolymer modification. Emerging directions such as engineered probiotic strains, spore-based carriers, and antioxidant nanozyme functionalization are also discussed. Through multi-dimensional comparisons of representative systems, we identify key considerations for optimizing delivery performance. Overall, intelligent delivery systems significantly improve probiotic gastrointestinal survival, achieve targeted release in specific intestinal segments, and enhance colonization through precision encapsulation design and synergistic trigger mechanisms. While challenges remain in manufacturing scalability, cost control, safety evaluation, and interindividual variability, these platforms establish a theoretical and technological foundation for advancing probiotic-based therapies and next-generation formulations.