Alginate oligosaccharide protects against enterotoxigenic Escherichia coli-induced porcine intestinal barrier injury.

Alginate oligosaccharide (AOS) possesses various pharmaceutical benefits, making it an attractive candidate for biomedical applications. In the present study, we prepared AOS by depolymerising alginate; its degree of polymerisation mainly ranged from 2 to 8. We confirmed the enteroprotective potential of AOS against enterotoxigenic Escherichia coli (ETEC)-induced intestinal barrier injury in weaned pigs. Next, we illustrated the mechanisms underlying this effect of AOS using the porcine small intestinal epithelial cell line IPEC-J2. AOS potently reduced the binding of the bacteria-deprived endotoxin lipopolysaccharide (LPS) to the IPEC-J2 cell surface. Moreover, it suppressed the LPS-induced production of pro-inflammatory cytokines and the nuclear translocation of nuclear factor-κB (NF-κB) p65 in IPEC-J2 cells. These results indicate that AOS protects the intestinal epithelium from ETEC-induced inflammatory injury by preventing the activation of NF-κB, implying that AOS could be used as an anti-inflammatory agent for treating inflammation-related intestinal diseases in mammals.