Polysaccharide-Based Encapsulation of Microbes for Enhanced Microbial Therapy.

The application of living microorganisms as therapeutics holds considerable potential but faces dual challenges of overcoming physiological barriers and host immune clearance. This review summarizes innovative encapsulation strategies using polysaccharide polymers to address these challenges. It begins by introducing encapsulation-compatible microbial taxa and the properties of major polysaccharide classes, including cationic, anionic, gel-forming, and neutral. Then, the review elaborates on two core functionalization strategies, namely non-covalent and covalent modification. It further analyzes key functions provided by polysaccharide encapsulation, such as protective effects, immunomodulation, targeted delivery, and synergistic therapy. Representative applications in treating tumors, bacterial infections, and inflammatory bowel diseases are summarized. Lastly, current challenges and future directions are discussed to guide the development of next-generation safe and effective microbial living therapeutics. This review positions polysaccharide-based encapsulation as a versatile platform for augmenting the therapeutic functionality of living microbial therapeutics.