Valorization of spent black tea polyphenols as a functional coating for probiotic protection and colitis alleviation

Nissle 1917 (ECN), resulting in the formation of ECN@SBT-Fe. This biomass-derived coating provided ECN with enhanced ROS scavenging abilities, improved survival under simulated gastrointestinal stress, and extended intestinal retention. In a mouse model of DSS-induced colitis, oral administration of ECN@SBT-Fe significantly reduced inflammation, restored epithelial barrier integrity, decreased oxidative stress, and effectively modulated gut microbiota by increasing diversity and promoting beneficial commensal bacteria. This research demonstrates a biomass-derived coating that serves as both a protective shield and a therapeutic agent, presenting a simple and sustainable encapsulation strategy for IBD treatment.