Mannose-glycosylated BSA and metal-phenolic network nanocoatings enhance gastrointestinal transit survival and intestinal adhesion of Lactobacillus plantarum B2.

Mannose-glycosylated bovine serum albumin (GBSA) offers enhanced intestinal adhesion capabilities through improved surface physicochemical properties and potential interactions with the intestinal mucosa. This study prepared the GBSA with a grafting degree of up to 91.07% in a natural deep eutectic solvent (NADES). BSA or GBSA was combined with EGCG/Ca2+ metal-phenolic networks (MPNs) to develop nanocoatings. Through layer-by-layer self-assembly, these coatings encapsulated the high-riboflavin-producing Lactobacillus plantarum B2 to enhance gastrointestinal survival and probiotic functionality. The results demonstrated that this encapsulation strategy achieved efficient probiotic loading and markedly improved storage stability. The coatings also fortified gastrointestinal transit tolerance and ROS defense of the encapsulated strain. Notably, the GBSA-based nanocoating enhanced adhesion to Caco-2 cells and prolonged intestinal fluorescence retention, while highly preserving the riboflavin-producing capacity of the probiotic. This single-cell encapsulation technology enables high survival rates and enhanced intestinal retention of a riboflavin-producing probiotic, showing considerable promise for functional food applications and dietary riboflavin supplementation.