Abstract: This study was aimed to observe the effects of microencapsulated Saccharomyces boulardii (S.boulardii) and Enterococcus faecium (E.faecalis) on ulcerative colitis (UC) and discuss its possible mechanism in mice.Mice model with UC was established by 3% dextran sulphate sodium (DSS),the test was divided into 6 groups,the model mice were randomized into 5 groups,mice were treated with unencapsulated-free E.faecalis,microencapsulated E.faecalis,unencapsulated-free S.boulardii and microencapsulated S.boulardii solution,respectively,and saline solution in DSS group by oral gavage.UC model mice (DSS group) were fed with the same volume of saline as the drug every day,while the normal control group was fed with the same volume of saline solution.The symptoms and histological changes of UC mice were observed,the pro-inflammatory cytokines including IL-6,IL-10 and TNF-α were measured by ELISA,and the expression of the Occludin and Claudin-1 were measured by Western blotting.The results showed that compared with DSS group,the contents of TNF-α and IL-6 were significantly reduced in probiotics groups (P<0.05),and the content of IL-10 was significantly increased (P<0.05).The myeloperoxidase activities and histoligical scores (except for unencapsulated-free E. faecalis group) were significantly decreased in microencapsulated pribiotics groups after treatment (P<0.05).The expression of Occludin and Claudin-1 were significantly increased inunencapsulated-free S.boulardii and microencapsulated S.boulardii groups(P<0.05).E.faecalis and S.boulardii could reduce the inflammatory lesions in the colon of UC mice,and the microencapsulated pribiotics had a better effect,moreover,the mechanisms of the improvement were possibly related to the decrease of the contents of IL-6 and TNF-α,and the increase of the expression of Occludin and Claudin-1.

Key words: emulsification gelation; microencapsulated probiotics; Saccharomyces boulardii; Enterococcus faecium; ulcerative colitis