[Effects of Faecalibacterium prausnitzii supernatant on Th17 cell and IL-17A in dextran sulfate sodium-induced ulcerative colitis mice].

OBJECTIVE

To explore the protective and therapeutic effects of Faecalibacterium prausnitzii (Fp) supernatant on ulcerative colitis (UC) in mice induced by dextran sulfate sodium (DSS) and the underlying mechanisms.

METHODS

Forty male mice were randomly divided into a control group, a model group, a treatment group and a prevention group (n=10 in each group). The colorectal histopathologic damage score (HDS) were calculated; the proportion of helper T cell (Th17) in mononuclear cells (MNC) in spleen, the levels of IL-17A and IL-6 in plasma were detected; the mRNA levels of transcription factor retinoic acid-related orphan receptor-γt (ROR-γt), interleukin (IL)-17A and IL-6 in colon mucosa tissues were also determined.

RESULTS

Compared with the model group, the colon HDS in the treatment group and the prevention group were significantly decreased (both P<0.05), but there was no significant difference in the treatment group and the prevention group (P>0.05). The proportion of Th17 cells in spleen in the treatment group and the prevention group was also remarkably lower than that in the model group (both P<0.01). The levels of IL-17A and IL-6 in plasma in the treatment group were significantly lower than those in the model group (both P<0.05). The mRNA expression of ROR-γt, IL-17A and IL-6 in the colon mucosa tissues in the treatment group were remarkably lower than those in the model group (all P<0.05). But there was no statistic difference in the level of IL-6 in the plasma and the colon mucosa tissues between the prevention group and the model group (P>0.05).

CONCLUSION

Fp supernatant has protective and therapeutic effects on ulcerative colitis in mice induced by DSS, which might be mediated by decrease of Th17 and IL-17A levels in the plasma and the colon mucosa tissues. Fp supernatant also can decrease mice colitis by reducing IL-6 levels.