Probiotics Improve Survival Of Septic Mice And Intestinal Microecology

Objective To explore the possible mechanism of probiotics in improving survival and gut microecology in sepsis mice.Methods Sixty 4-week-old C57BL6 male mice were randomly divided into three groups,Probiotics+ Septic(n = 20),Control Septic(n = 20)and Sham(n=20).200?l/day of BIFICO(Live Combined Bifidobacterium,Lactobacillus and Enterococcus Powder?1.0×107CFU)or normal saline(control)was orally administrated for 4 weeks prior to CLP.10 of each group were used for survival studies,and the remaining were sacrificed 24h after CLP.Pro-inflammatory cytokines in serum(IL-22.IL-2?TNF-a)were determined by the ELISA method and HE stained colon slices were used to observe the morphology of Colonic mucosal structure and the expression of occludin was observed by immunohistochemistry.The fecal bacteria composition was investigated by 16S rDNA gene.The experimental data were expressed as mean ±standard deviation and One-way analysis of variance(One Way ANOVA),Boferroni test or Tamhane's T2 test for multiple hypothesis test corrections.Survival.analysis using the log-rank test Kaplan-Meier survival curve.Results The 7-day survival of the Probiotics+ Septic was significantly higher than the Control Septic(P=0.042).All three inflammatory factors were elevated in Control Septic.After probiotics intervened early,IL-22 and IL-2 levels were still higher than Sham(P<0.001),but significantly lower than the control sepsis group(P<0.001).),suggesting that probiotics help reduce the body's inflmmnatory response.TNF-a was higher than Sham in serum of 2 sepsis groups(P<0.001).Pre-administration of probiotics did not reduce TNF-a in Probiotics+Septic group.Ileum mucosal damage was evident in the Control Septic.Occludin was lower in colonic epithelial cells of sepsis mice.The 16SrDNA revealed a significant increase in Bacteroide in the Control Septic group(P<0.001)and a significant decrease in Firmicutes(P<0.001).Probiotics+Septic group was close to the Sham group without statistical significance difference.Proteobactria was close to the two sepsis groups with no statistical difIference.Compared with the Sham group,the abundance was significantly increased(P<0.001).At the family level,the Bacteroide S24-7 in the Control Septic group was significantly increased(P<0.001).In the order of Clostridium perfringens was significantly reduced(Probiotics+Septic vs vs Control Septic Pp-c=0.006;Control Septic vs.Sham Pc-s=0.048)and the Probiotics+Septic group was similar to the Sham group;with no statistical difference. The Proteobacteria Helicobacteraceae was similar in the two sepsis groups,with no statistical difference,and a significant increase over the Sham group(Probiotics+Septic vs.Control Septic Pp-s<0.001;Pc-s<0.001);Desulfovibrionaceae in Probiotics+Septic group was significantly lower than Control Septic(P=0.021),and Sham was located between the two groups without statistical differences.The pre-administration of probiotics can stabilize the intestinal microflora in sepsis mice at the main phylum and family level,which is not conducive to the reduction of harmful bacteria.Conclusions Pre-administration of probiotics can stabilize the microecological balance of the intestine and inhibit the release of inflammatory factors,thereby maintaining the intestinal mucosal barrier structure and function,reducing the loss of intestinal connective protein,inhibiting intestinal barrier penetration,and improving the survival of sepsis mice.But it not conducive to the reduction of harmful bacteria...