Anti-inflammatory and gut microbiota-modulating effects of a novel mannan from Scilla scilloides on DSS-induced colitis in mice

Scilla scilloides is a traditional plant with medicinal and nutritional value, known for its diverse biological activities. This study aimed to identify the structure of a novel polysaccharide SCSP-W from Scilla scilloides and evaluate its anti-colitis activity. SCSP-W is primarily composed of mannose, rhamnose, galacturonic acid, galactose, and arabinose in a molar ratio of 66.7:6.1:3:18.1:6.1. Nuclear magnetic resonance spectroscopy and methylation analysis confirmed that SCSP-W is a mannan with a well-defined structure. In DSS-induced colitis mice, SCSP-W significantly alleviated inflammation, restored gut function, and exhibited strong therapeutic potential. It effectively regulated inflammatory cytokines, including TNF-α, IL-6, IL-17, and IL-10, while enhancing intestinal barrier-associated proteins. Additionally, SCSP-W restored the abundance of beneficial gut bacteria, including Lactobacillus, Spirochaeta , and Desulfovibrio , which play essential roles in gut health and colitis symptom relief. Its ability to modulate gut microbiota suggests a prebiotic-like function, further supporting its therapeutic potential. In short, the SCSP-W multi-targeted effects on inflammation, intestinal integrity, and microbial composition highlight its potential for developing functional foods or pharmaceuticals for inflammatory bowel diseases.