Effect Of Soluble Dietary Fiber On Intestinal Mucus Barrier In Septic Mice

At present,sepsis has been one of the major causes of death worldwide,it is also our country pay more and more attention to the public health problem.Sepsis is a clinical syndrome that causes multiple organ dysfunction in the body due to the misalignment of the host's response to the infected pathogen.In recent years,more and more research has been related on intestinal barrier function and sepsis.More and more scholars agree that in the development of sepsis,due to the changes of intestinal microenvironment caused by the increase of intestinal mucosal permeability,a large number of endotoxin into the blood,thus inducing the body's inflammatory response.The metabolic product of dietary fiber,short-chain fatty acids,which is a source of energy for intestinal microorganisms,short chain fatty acids by strengthening mucus production and promote the development of regulating T cell help regulate intestinal mucosal immunity,inhibit inflammation signal conveying.This paper intends to explore whether dietary fiber can improve intestinal mucus barrier and improve the clinical symptoms of sepsis by improving gut microecological,thus helping to provide a new direction for the treatment and prevention of sepsis.Objective: To observe the effect of soluble dietary fiber on intestinal mucus barrier in septic mice,and to explore the protective mechanism of soluble dietary fiber on sepsis.Methods: The experimental use of clean grade C57BL/6 male mice,6-8 weeks old,body weight 18-23 g,adaptive breeding after a week into the experiment.The experimental animals were randomly divided into four groups by random number method,that is,sham Operation Group(Sham Group,SH Group)(N=12),Sepsis Model group(CLP Group,Group C)(n=24),Sepsis Treatment Group(treatment Group,T Group)(N=24),Verification Group(validation group,V Group)(n=24).All animals eat and drink freely.SH group only Caesarean section,do not do cecum ligation perforation,c Group,T Group,v Group with cecum ligation perforation caused by sepsis model.Sh,group C to give the basic feed + pure water feeding,T Group to give the basic feed + soluble dietary fiber drinking water feeding,v Group to give the basic feed + soluble dietary fiber drinking water + antibiotic drinking water feeding;Antibiotics include vancomycin(0.5g/l),metronidazole(1g/l)and ampicillin(1g/l);basic feed purchased from Beijing Huatong Huali Experimental Animal Technology Co.,Ltd.,each 100 g heat for 348kcal;10.3%,protein 24.2%,the rest for carbohydrates;soluble dietary fiber purchased from Beijing and Zeckanchen Medical Technology Co.,Ltd.(Ingredients: low-poly galactose,fructose,oligosaccharides).4 mice were executed in 1/4/7 days,and the severed heads were taken to death and recorded.Blood was collected to determine the-1?(IL-1?),tumor necrosis factor-alpha(tnf-?),D-lactic acid;To observe the general condition of the viscera;to observe intestinal villi completeness of the intestine tissue,and to observe the thickness of the mucus layer by Alibin blue-over-iodide Shelley staining in the colon tissue.The expression of intestinal mucosal protein(MUC2)was observed by Immunohistochemical method.Results:1.Mortality level:There was no death in SH Group,24 hours survival rate in Group C was 62.5%,96 hours survival rate was 75%,24 hours after operation,96 hours survival rate was 58.9%,significantly better than in CLP group mice(P <0.05),24 hour survival rate in V Group was 30% hours,Significantly lower than the T Group(P <0.05).2.Serum TNF-?(NG/ML),IL-1?(NG/ML)Levels: Serum TNF-?(380.33±66.67)and IL-1?(267.71±11.88)levels in group C mice on the 1th day after surgery were relative to the Sh group TNF-?(30.27± 9.59)and IL-1?(62.59±3.40)significantly increased(P<0.05),T mice serum TNF-?(72.47±11.66)andC(63.48±8.12)levels were significantly lower than group C(P <0.05);Compared with the T group,Serum TNF-?(369.48±86.26)and IL-1?(109.68±6.22)levels in V-group mice increased significantly(P <0.05).The content of serum TNF-? and IL-1? in each group decreased gradually with the prolongation of survival time.3.Serum D-Lactic acid(NG/ML)level: In the 1th Day Sh Group Serum D Lactic Acid concentration(2.82±0.12)was lower than that of CLP(3.72±0.11),T Group(3.07±0.01)and V Group(3.60±0.16).The serum D lactic acid concentration in T group was significantly lower than that in group C(P <0.05),and the V group was significantly higher than that in T group(P <0.05).The content of D lactic acid in each group decreased gradually with the prolongation of survival time..4.Colon mucus layer thickness(UM)level: On the 1th day compared with the Sh group(42.61±1.05),the mucus layer thickness(24.67±0.90)in group C mice was significantly thinner(P <0.05),compared with group C,the thickness of mucus layer(42.87±1.68)in T-group mice increased significantly(P < 0.05);Compared with the T group,the thickness of mucus layer(24.81±0.92)in V-group mice was significantly thinner(P <0.05).The thickness of mucus layer in each group increased gradually with the prolongation of survival time.5.Histopathological results:(1)Intestinal tissue HE staining results: under light microscope(40x10),SH group intestinal villi villi were complete,arranged rules,the epithelial layer and the inherent layer were closely connected,no capillary dilatation congestion,the 1th day of Group C can be seen intestinal villi sparse,disordered arrangement,continuous fracture,Visible epithelial clearance with local villi shedding,visible inflammatory cell infiltration,the 4th day can be seen intestinal villi sparse than before reduction,intestinal villi arrangement is neat,tight,lower epithelial clearance than before.Compared with group C,the basic morphology of T Group intestinal villi in the 1th day was normal and neatly arranged,the epithelial space was slightly dilated,the inherent layer was intact,and the inflammatory cells infiltrated less.On the 4th day intestinal villi slightly shorter than before,arranged neatly,and the subcutaneous clearance was significantly better than before.On the 1th day of the V Group,intestinal villi sparse,mild shedding at the top of the villi,sparse arrangement,continuous fracture,visible epithelial clearance and with part of the villi apex shedding.The structure of the 7th day and the 4th day of each group was similar,and there was no significant difference.6.Immunohistochemistry: On the 1th day,the expression of intestinal mucosal MUC2 protein(0.29±0.02)in Group C was significantly lower than that of SH Group(0.35±0.01),and T Group(0.32±0.02)increased compared with Group C expression.V Group(0.25±0.02)decreased compared to T group expression.MUC2 expression increases gradually with the prolongation of survival time.Conclusion:1.Complementary dietary fiber can improve the survival rate by improving metabolic endotoxemia,inhibiting the release of inflammatory media,reducing the inflammatory response of the body.2.Dietary fiber supplementation maybe improved intestinal flora disorder in septic mice,and the use of antibiotics offset the benefits of dietary fiber supplementation.3.Complementary dietary fiber can improve the function of intestinal mucosal chemical barrier and reduce intestinal permeability.