A Study On Remission Mechanism Of Lactobacillus Plantarum ZDY2013 And Bifidobacterium Bifidum WBIN03 On Colitis Mice

Inflammatory bowel disease?IBD?had become one of the most important diseases that threatened human health,and it was easy to recur.IBD was mainly influenced by genetic,environmental,immune and intestinal microflora factors.Probiotics could improve the structure of intestinal microflora,which were commonly used inprevention and treatment,or assist in the treatment of a variety of diseases.In this study,Lactobacillus.plantarum ZDY2013?L.plantarum ZDY2013?from acid beans,Bifidobacterium.bifidum WBIN03?B.bifidum WBIN03?from infant feces and their mixture with the ratio of 1:1,to investigate their anti-inflammatory and antioxidantion the effect on H₂O₂-induced HT-29 cell oxidation damaged model.The activity of antioxidant enzymes increased significantly after the cell incubated with the bacterium suspension mixture?P<0.05?.The activity of T-SOD in HT-29 cell supernatants significantly increased in the B.bifidum WBIN03 group?P<0.05?,while GSH-P_X activity significantly increased in both L.plantarum ZDY2013 and B.bifidum WBIN03 groups?P<0.05?.SOD1 expression was significantly up-regulated in the B.bifidum WBIN03 group?P<0.05?,SOD2 and GPX2 were both up-regulated in the L.plantarum ZDY2013 group?P<0.05?.The mixture of two strains significantly improved the expression levels of SOD1 and GPX2?P<0.001?.The single strain and the mixture treatments significantly reduced the expression of IL-6 but up-regulated that of IL-10?P<0.05?.Based on the in vitro protection effect on HT-29 cell line,we further examined the in vivo protection of the two strains in DSS-induced ulecrative colitis?UC?models and TNBS-induced Crohn's disease?CD?models using 4-5 weeks BALB/c mice.The general relative indexes results?body weight and colon histopathology?showed that L.plantarum ZDY2013 and B.bifidum WBIN03 had positive effect on DSS-induced and TNBS-induced colitis mice.The activity of antioxidant enzymes?SOD,GSH-Px,CAT?had been improved in serum through down-regulating the transcriptional level of pro-inflammatory cytokine?TNF-??and up-regulating those of anti-inflammation factor?IL-10?and antioxidant factors?SOD1,SOD2,GPX2,CAT?.In the UC mice experiment,the relative expression of Nrf2 was significantly increased under the action of two strains?P<0.05?.To better understand the structure and transformation of intestinal flora,this study investigated the differences of intestinal microbiota among all groups using 16S rDNA gene sequencing in UC mice fecal.LefSe analysis showed that administration of L.plantarum ZDY2013 increased the abundance of Lactobacillus-animals,while B.bifidum WBIN03increased the abundance of Lachnospiracea-bacterium-COE1.The results of LefSe analysis and MetaStat analysis showed that the effects of the two strains on the intestinal microflora of DSS induced colitis in mice mainly concentrated on the Firmicutes,Bacteroidetes and Proteobacteria.The above researches showed that L.plantarum ZDY2013 and B.bifidum WBIN03 could relieve colitis by regulating the flora diversity and immunity of colitis mice and improving the activity of antioxidant enzymes.This study provided a theoretical basis for the addtion of probiotics to medication to relieve IBD.