Effects of different galactans on DSS-induced colitis and the gut microbiota

Bioactive galactans are widely distributed in nature, with some extensively reported for their potential in modulating the gut microbiota and intestinal inflammation. However, the efficacy of different galactans in ameliorating colitis remains unclear. Our study systematically compared the effects of three nonlinear galactans (Hericium erinaceus polysaccharides, HEP; Lycium barbarum polysaccharides, LBP; larch arabinogalactan, LAG) and two linear galactans (agarose, AGR; carrageenan, CGN) on colitis in mice. The results indicated that HEP, LBP and LAG treatments significantly alleviated colitis symptoms, regulated the inflammatory cytokines and improved intestinal barrier function. Notably, they could modulate the gut microbiota by promoting the relative abundance of probiotics such as S24-7, Lactobacillus and Bacteroides, while suppressing the proliferation of pathogenic bacteria like Enterobacteriaceae. In contrast, AGR and CGN showed no significant alleviative effects on most indicators. This study highlights the efficacy of different types of galactans in treating colitis and modulating the gut microbiota, providing a theoretical basis for the development of dietary polysaccharide-based intervention strategies for IBD.