Abstract

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder characterized by symptoms such as diarrhea, bleeding, and an elevated risk of colorectal cancer. Bacterial extracellular vesicles (EVs) have emerged as a promising delivery system for bioactive compounds, owing to their high biocompatibility, low immunogenicity, and cost-effectiveness. In this study, EVs were isolated from two Lactic acid bacteria (LAB) -Lactobacillus delbrueckii ssp. Bulgaricus and Streptococcus thermophilus , and curcumin was successfully encapsulated into these vesicles. Compared with those derived from S. thermophilus , the curcumin-loaded EVs from L. bulgaricus (L-EVs-C) demonstrated superior characteristics, including optimized particle size, higher encapsulation efficiency, e n hanced antioxidant capacity, and improved gastrointestinal stability. In a DSS-induced colitis mouse model, L-EVs-C treatment significantly alleviated disease symptoms, and positively modulated the gut microbiota and enriching beneficial bacteria. These results underscore the potential of natural probiotics EVs as effective nanocarriers for bioactive compounds in the development of functional foods and therapeutic strategies.