A polysaccharide from yogurt fermented by Lactobacillus bulgaricus and Streptococcus thermophilus: Structural characteristics and its alleviative effect on DSS-induced colitis in mice

[Display omitted] •A novel polysaccharide (EPS-1) isolated from yogurt and characterize its structure.•EPS-1 reduces gut mucosal damage, inflammatory factors, and restores SCFAs levels.•EPS-1 restores gut flora disorders and maintains the balance of gut flora.•In situ production of EPS-1 in yogurt shows potential as a functional food. Polysaccharides have recently garnered interest for their possible biological activity in treating colitis. In this work, we isolated a novel polysaccharide EPS-1 from yogurt, which comprises galactose and glucose (molar ratio = 42.04:57.96) and has a molecular weight of 32.60 kDa on average. The structure characterization revealed that EPS-1 exhibits an amorphous sheet structure with a smooth surface, comprising five distinct glycosidic bonds in its repeating units. The animal experiments showed that EPS-1 might alleviate dextran sulfate sodium-induced colitis by decreasing damage to the intestinal mucosa, intestinal barrier, and inflammatory factor levels, restoring short-chain fatty acids levels, and keeping the balance of intestinal flora. Our findings indicated that EPS-1, which is produced in situ during yogurt fermentation, holds promising potential for the prevention and management of colitis.