Encapsulation and Functional Activity of <i>Lactobacillus reuteri</i> Strains: Advances, Challenges, and Perspectives

Over the past decade, probiotics have gone from been special health supplements to widely incorporated components in many foods and nutrition products. This has led to more careful checks of their safety, viability, and functional performance under realistic processing and consumption conditions. Within lactic acid bacteria, Limosilactobacillus reuteri (formerly Lactobacillus reuteri) has been extensively investigated for its immunomodulatory, antimicrobial, anti-inflammatory, antioxidant, and metabolic properties as demonstrated across multiple in vivo and in vitro experimental models. Despite these functional attributes, its viability during food processing and gastrointestinal transit remains strongly influenced by the strain and the characteristics of the delivery matrix; as a result, encapsulation is an essential strategy to preserve cellular integrity and functionality. The present review examines the functional properties of Limosilactobacillus reuteri (L. reuteri or LR) strains alongside the technological approaches used for their encapsulation. Current encapsulation approaches, including ionic gelation, extrusion, electrospray, and spray drying combined with biopolymers to improve encapsulation efficiency and survival of strains such as DSM 17938 and DSM 20016, are discussed with emphasis on their applicability to probiotic delivery and the formulation of functional foods with potential to improve gastrointestinal health, modulate inflammation, and enhance metabolic functions. In addition to strain-specific functional activities, this review examines how coating material, processing method, and strain affect release kinetics, functional activities, and viability. However, data on the stability of encapsulated L. reuteri during industrial processing, storage, and health claim validation under regulatory frameworks remain limited. Future research should address these challenges to support the use of L. reuteri in functional foods and therapeutic products.