As an intractable disease recognized by the WHO, current available treatments have limitations for ulcerative colitis (UC) . Although the effectiveness of fecal microbiota transplantation (FMT) has been confirmed, the reported efficacies are various.

To compare the effect of FMT between a mouse model of common UC and a mouse model of damp-heat UC, and the medicinal flavor of fecal microbiota (new jinzhi) .

This experiment was implemented from December 9th to 28th, 2019. Thirty-five male SPF C57BL/6 mice were equally divided into seven groups: normal control group (no intervention) , common UC model (CUCM) group (received interventions to be a CUCM according to the requirements) , CUCM+FMT group (received interventions to be a CUCM successfully, then received an enema of 0.2 ml prepared fecal microbiota solution) , CUCM+5-aminosalicylic acid (5-ASA) group (received interventions to be a CUCM successfully, then received an enema of 0.019 5 g/ml 5-ASA) , damp-heat UC model (DUCM) group (received interventions to be a DUCM according to the requirements) , DUCM+FMT group (received interventions to be a DUCM successfully, then received an enema of 0.2 ml prepared fecal microbiota solution) , and DUCM+5-ASA group (received interventions to be a DUCM successfully, then received an enema of 0.019 5 g/ml 5-ASA) . The intestinal tissues of each group of mice were taken out when the experiment ended, and were stained with H&E for observing the morphology, and ultrastructure of them was observed using transmission electron microscope, Th1 and Th2 cells in them were detected using flow cytometry, and microbial community in them were detected using high-throughput 16S rRNA gene sequencing. Routine blood test was conducted to measure the levels of white blood cell count (WBC) , red blood cell count (RBC) , platelet count (PLT) and hemoglobin (HGB) . Nimodipine method was used to evaluate the efficacy index before and after intervention.

The mice in each group were successfully established. The morphology of intestinal tissues stained with H&E: the intestinal mucosal surface of CUCM group and DUCM group had different degrees of defect or shedding and necrosis, while the intestinal mucosa was basically intact in CUCM+FMT group, CUCM+5-ASA group, DUCM+FMT group and DUCM+5-ASA group. The DUCM+FMT group had more neatly arranged and compacted glands than did CUCM+FMT group. The ultrastructure of intestinal tissue observed using transmission electron microscope: the surface microvilli of epithelial cells in CUCM and DUCM groups were sparse with decreased goblet cells. The CUCM+FMT, CUCM+5-ASA, DUCM+FMT and DUCM+5-ASA groups had denser microvilli with more goblet cells. Compared with the CUCM+FMT group, the DUCM+FMT group had denser microvilli and more goblet cells. Th1 and Th2 cell contents: there were significant differences in Th1 and Th2 cell contents, WBC, RBC, PLT and HGB across all groups of mice (P<0.001) . Efficacy analysis: the efficacy index of CUCM+5-ASA group, DUCM+FMT group or DUCM+5-ASA group was better than that of CUCM+FMT group (P<0.05) . Microbial community analysis: the genus with significantly decreased abundance in CUCM and DUCM groups was Ruminococcus, and the increased abundance was Akkermansia. The CUCM+FMT and DUCM+FMT groups had a tendency of gradually increasing similarities to the control group, indicating that the intestinal flora of these two groups were improving.

FMT were effective for mice models of UC, especially for the mice model of damp-heat UC. The new jinzhi has a bitter and cold flavor, which may work by regulating the intestinal flora to improve the Th1/Th2 balance for therapeutic purposes.