Effect of Banxia Xiexin Decoction on intestinal flora of mice with ulcerative colitis induced by dextran sodium sulfate

The aim of this paper was to investigate the effect of Banxia Xiexin Decoction(BXD) on inflammatory factors and intestinal flora in a dextran sulfate sodium induced ulcerative colitis(DSS-UC) mouse model, and to explore the mechanism of BXD in treating ulcerative colitis from the perspective of flora disorder. Forty C57 BL/6 J mice were randomly divided into control group, model group and BXD group. A 2.5% DSS-induced ulcerative colitis model was established. On the 8 th day, normal saline, normal saline, and BXD were given daily for 14 days. After 14 days, HE staining was used to observe histopathological changes of the colon. Serum inflammatory factor content was detected by ELISA, and the change of intestinal flora in mice feces was detected by 16 S rRNA sequencing technology. Compared with control group, the colonic tissue of mice in model group was damaged seriously, and the contents of IL-6 and TNF-α in serum were significantly increased(P<0.05). Compared with model group, mice in BXD group had less colonic damage, and the contents of IL-6, TNF-α in serum were decreased significantly(P<0.05). After creation, the richness of Patescibacteria was increased significantly at the phylum level(P<0.05). At the same time, the richness of Faecalibaculum(P<0.01), norank_f_Muribaculaceae(P<0.01) were decreased significantly at the genus level, while the richness of Turicibacter(P<0.01), Romboutsia(P<0.01), Clostridium_sensu_stricto_1(P<0.01) were increased significantly. After the intervention with BXD, the content of Patescibacteria was significantly reduced at the phylum level(P<0.05), and the contents of Lactobacillus(P<0.01), Clostri-dium_sensu_stricto_1(P<0.01), Enterorhabdus(P<0.01), Candidatus_Saccharimonas(P<0.05), Eubacterium_fissicatena_group(P<0.05) were decreased significantly at the genus level, while the contents of Dubosiella, Bacteroides and Allobaculum were increased significantly. Therefore, BXD could significantly improve the symptoms of DSS-UC mice. It not only could reduce the contents of IL-6 and TNF-α, but also could reduce the richness of Patescibacteria at the phylum level, and those of Clostridium_sensu_stricto_1, Candidatus_Saccharimonas, Eubacterium_fissicatena_group at the genus level. Inaddition, BXD could increase the richness of Bacteroides and Bifidobacterium. It suggested that BXD could play a role in the treatment of ulcerative colitis partially through reducing inflammatory factors and regulating the structure of the gut microbiota.