In Vitro Assessment of Bacillus thuringiensis Exopolysaccharides and Their Effects on Gut Microbiota from Ulcerative Colitis In Vitro

<i>Bacillus thuringiensis</i> exopolysaccharide BPS-2 inhibits malondialdehyde secretion, enhances antioxidant enzyme activities, and significantly improves the antioxidant status of inflammatory cells. In the present study, the apparent morphology and spatial conformation of BPS-2 were analyzed further, and several functional properties were investigated. The results demonstrated that BPS-2 was a polymeric straight-chain polysaccharide with good thermal stability, exhibiting non-Newtonian properties and good antioxidant and anticancer activities. Notably, this study systematically investigated the impact of BPS-2 on the intestinal microbiota composition in patients diagnosed with ulcerative colitis. Through in vitro fermentation of fecal bacteria collected from six volunteers, it was found that BPS-2 exerted a positive influence on the intestinal flora of ulcerative colitis patients, augmenting the secretion of short-chain fatty acids and facilitating an increase in the relative abundance of <i>Bifidobacterium</i> spp. These results suggest that BPS-2 has the potential to be a food additive for suppressing ulcerative colitis and for other medically related applications.