Dual-layer probiotic encapsulation using metal phenolic network with gellan gum-tamarind gum coating for colitis treatment

Probiotic oral therapy has been recognised as an effective treatment for inflammatory bowel disease (IBD). However, the efficacy of probiotics is often diminished due to their limited resistance to harsh gastrointestinal conditions. Therefore, the importance of designing innovative strategies for oral probiotic delivery for the effective treatment of IBD is increasingly recognised. In this study, we present a novel encapsulation strategy of Lactobacillus plantarum (L.P) using the dual-layer system consisting of a tannic acid‑calcium network and polysaccharide coating (gellan gum-tamarind gum) named L.P-C/T-G/T. This double-layer encapsulation system not only does not affect the normal proliferation of probiotics and provide protection, but also endows probiotics with more functions. More specifically, the acid resistance ability of the encapsulated probiotics is increased by 10 times, the free radical scavenging rate is enhanced by 5 times, and the intestinal retention time can be prolonged by 6-12 h. In the DSS-induced murine colitis model, it significantly alleviated colon shortening, inhibited ROS overexpression, and promoted the repair and regeneration of the mucus layer. This dual-layer encapsulation approach for a single probiotic demonstrates a significant advancement in probiotic delivery technology, offering hope for a comprehensive approach to the treatment of colitis and potentially other gastrointestinal disorders.