Amelioration of enterotoxigenic Escherichia coli-induced disruption of intestinal epithelium by manno-oligosaccharide in weaned pigs

To explored the protective effect of manno-oligosaccharides (MOS) on intestinal epithelium exposure to Enterotoxigenic Escherichia coli (ETEC), thirty-two pigs were assigned into four treatments and fed with basal or MOS-containing (0.3% MOS) diet. Pigs were challenged by ETEC or culture medium. Results show that MOS not only reduced diarrhea incidence and fecal E. coli abundance but decreased serum D-lactate and DAO concentrations upon ETEC-challenge (P < 0.05). Interestingly, MOS attenuated ETEC-induced intestinal injury, as indicated by improved mucosa morphology and tight-junction protein distribution and decreased cell apoptosis. MOS also increased sIgA, GSH-Px, and SOD contents in jejunum (P < 0.05). Importantly, MOS down-regulated genes involved in inflammatory responses (TNF-α, IL-1β, TLR4, and NF-κB) and apoptosis (Caspase 3, Caspase 9, and Bax), but up-regulated expressions of antioxidant genes (HO-1 and Nrf2) (P < 0.05). These results suggested that MOS can alleviate ETEC-induced intestinal injury, which was associated with suppressed inflammation and improved antioxidant capacity and intestinal epithelial functions.