Mannan oligosaccharides selenium ameliorates intestinal mucosal barrier, and regulate intestinal microbiota to prevent Enterotoxigenic Escherichia coli -induced diarrhea in weaned piglets.

Enterotoxigenic Escherichia coli (ETEC) is a common diarrheal pathogen in humans and animals. To prevent and treat ETEC induced diarrhea, we synthesized mannan oligosaccharide selenium (MOSS) and studied its beneficial effect on ETEC-induced diarrhea. A total of 32 healthy weaned piglets (6.69 ± 0.01 kg) were randomly divided into four groups: NC group (Basal diet), MOSS group (0.4 mg/kg MOSS supplemented diet), MOET group (0.4 mg/kg MOSS supplemented diet + ETEC treatment), ETEC group (ETEC treatment). NC and ETEC group fed with basal diet, MOSS and MOET group fed with the MOSS supplemented diet. On the 8th and 15th day of the experiment, MOET and ETEC group were gavaged with ETEC, and NC and MOSS group were gavaged with stroke-physiological saline solution. Our data showed that dietary MOSS supplementation increased average daily gain (ADG) and average daily feed intake (ADFI) and significantly decreased diarrhea index and frequency in ETEC-treated piglets. MOSS did not affect the α diversity and β diversity of ileal microbial community, but it significantly decreased the proportion of lipopolysaccharide biosynthesis in ileal microbial community. MOSS supplementation regulated colonic microbiota community composition, which significantly increased carbohydrate metabolism, and inhibited lipopolysaccharide biosynthesis pathway in colonic microbial community. Moreover, MOSS significantly decreased inflammatory stress, and oxidative stress in ETEC treated piglets. Furthermore, dietary MOSS supplementation significantly decreased intestinal barrier permeability, and alleviated ETEC induced intestinal mucosa barrier irritation. In conclusion, our study showed that dietary MOSS supplementation ameliorated intestinal mucosa barrier, and regulated intestinal microbiota to prevent ETEC induced diarrhea in weaned piglets.