Exopolysaccharides from Bacillus amyloliquefaciens DMBA-K4 ameliorate dextran sodium sulfate-induced colitis via gut microbiota modulation
Jia‐hua Kuang, Yanyan Huang, Jin‐shuang Hu, Jiajia Yu, Qin‐yu Zhou, Dongmei Liu
Abstract
Accumulating evidences have reported that polysaccharide could alleviate colitis through the maintenance of intestinal homeostasis. In this study, an exopolysaccharide (EPS-K4) from Bacillus amyloliquefaciens was obtained via anionic-exchange chromatography which was with an average molecular weight of 10,067 Da and consisted of mannose, rhamnose, glucuronic acid, and glucose with a molar ratio of 40.09:23.65:11.42:17.68. Furthermore, administration of EPS-K4 relieved symptoms in colitis mice via gut microbiota modulation. The levels of pathogenic bacteria, such as Enterococcus and Escherichia-Shigella, were significantly suppressed. In contrast, the levels of Lactobacillus and intestinal microbiota diversity were increased. EPS-K4 could stimulate mucin secretion to maintain the integrity of the gut barrier and decrease the levels of virulent substances (endotoxin, diamine oxidase, and D-lactic acid) in serum. The pro-inflammatory cytokines (TNF-α) in serum were reduced, conversely, anti-inflammatory cytokines (IL-10) were increased. These findings indicated the possibility of EPS-K4 as a chemotherapy candidate for the prevention of colitis.