Abstract: Objective: To investigate the intervention effect of chitooligosaccharide (COS) on intestinal injury induced by chronic drinking. Methods: Male Wistar rats were randomly divided into five groups: blank control, model, low-, medium-, and high-dose COS treatment groups. The rats in all groups except the blank control group were intragastrically administered with 4.5 g/kg mb of alcohol for 42 successive days to induce intestinal injury, which was preceded by COS for the treatment groups. Results: COS could significantly improve the performance of the rat duodenal?smooth muscle (P < 0.05), restore small intestinal health, significantly reduce the concentration of D-lactic acid (D-LA), diamine oxidase (DAO) activity, the levels of pro-inflammatory cytokines including interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6, malondialdehyde (MDA) concentration and protein carbonyl content in plasma (P < 0.05) and claudin-4 gene expression (P < 0.05), and significantly inhibit the gene expression of claudin-4 (P < 0.05). High-dose COS could significantly increase the gene expression of the tight junction proteins occludin and ZO-1 (P < 0.05). Medium- and high-dose COS could significantly reduce gene the expression of IL-6, IL-1β and TNF-α in the duodenum (P < 0.05). Conclusion: COS alleviates intestinal damage caused by chronic drinking in rats by improving small intestinal health, enhancing intestinal mucosal barrier, reducing inflammatory responses and alleviating oxidative damage.

Key words: chitooligosaccharide; alcohol; intestinal mucosal barrier; inflammatory response; oxidative damage