The Protective Effect Of FMT On The Liver And Intestinal Mucosal Barrier In NAFLD Rats

Nonalcoholic fatty liver disease(NAFLD)is a chronic liver disease with high incidence rate,which includes simple nonalcoholic fatty liver,nonalcoholic steatohepatitis(NASH)and cirrhosis.The pathogenesis of NAFLD is complex.With the raising of the theory of "liver intestine axis" and the further study of the intestinal micro ecology,the role of intestinal mucosal barrier function has been emphasized in the pathogenesis of NAFLD.Studies have shown that there is intestinal mucosal barrier dysfunction and changes of intestinal flora in NAFLD rats.Normal intestinal flora can constitue the natural gut mucosal barrier,more and more researches have indicated that probiotics can improve the intestinal mucosal barrier function by adjusting the intestinal flora,and play an important role in the treatment of NAFLD.As a special probiotics,FMT is mainly used in the treatment of Clostridium difficile infection(CDI)and has achieved an effective outcome.At present,there are many kinds of probiotics,which contain the limited species of bacteria.The FMT contains almost all the intestinal flora of the receptors,which can quickly recover the normal intestinal flora composition and improve the function of intestinal mucosal mechanical barrier,then achieve the purpose of treating diseases.Therefore,we assume that FMT may have a certain effect on the treatment of NAFLD and metabolic disease.Objective:To explore the protective effects of FMT on liver and intestinal mucosal barrier of NAFLD rats and to provide the experimental evidence for the treatment of FMT in NAFLD and metabolic disease.Methods:Thirty healthy male Sprague-Dawley rats(weighted 180 ± 20g)were randomized into three groups after adaptive feeding for a week,the control group(group C),the model group(group M)and the treatment group(group T),10 rats in each group.Normal diets were given to group C,which were provided by the experimental animal center of Hebei Medical University.Rats in group M and group T were provided with high-fat diets,in which the fat content was 59.8%.The materials of high-fat diet were also provided by the animal experimental center of Hebei Medical University.After 12 weeks later,rats in each group were randomly killed,using Sultan black B staining to determine whether the models were successed.Then rats in group T were given 2ml fecal bacteria liquid by intragastric administration every other day.In the night before FMT and the morning of the day,they received Omeprazole Magnesium Enteric-coated Tablets in a dose of 10mg/kg by gavage,in order to reduce the pH of gastric.At the same time,rats in group C and group M were also given the same amount of normal saline and Omeprazole Magnesium Enteric-coated Tablets.In the 16th weeks,all of the rats were sacrificed in anesthesia by abdominal aorta bleeding.Blood samples of rats were obtained from the abdominal aorta.Level of plasma endotoxin and serum TNF-a,ALT,AST,TG were assaied.The changes of liver were observed by Sudan Black B staining and HE staining.The changes of intestinal mucosa structure were observed by HE staining and scanning electron microscope.Results:1 Changes of general condition after feeding for 12 weeks:The Sudan Black B staining results showed that the liver cells of group M and group T were filled with fatty deposition,and the results showed that the model was successful.Compared with group C,weight of rats in group M and group T were significantly higher,the differences were statistically significant(P<0.05),there was no obvious difference between the group M and group T(P>0.05).2 Changes of weight in the 16th weeks of rats:The body weight in group M was significantly higher than group C,and the difference was statistically significant(P<0.05).Compared with the group M,the weight of rats in group T was decreased(P<0.05).3 The blood test results:Compared with the level of TG,ALT,AST in group C,level of TG,ALT,AST in group M was significantly higher,the difference was statistically significant(P<0.05).Compared with group M,level of TG,ALT,AST in group M was decreased,the difference was statistically significant(P<0.05).Compared with group C,level of endotoxin,TNF-? in group M was significantly increased,the difference was statistically significant(P<0.05).Compared with group M,level of endotoxin,TNF-? in group T was decreased,the difference was statistically significant(P<0.05).4 Pathological alteration of liver1)The Sultan black B staining of liver:The blue fat deposition in the liver cells of group C was not obvious.In group M,the volume of liver cells was increased,showing a large number of black fat deposition in the liver cells,hepatic steatosis is obvious.After receiving the FMT,the fat deposition in the liver cells of group T was significantly reduced,and the degree of steatosis was reduced,which compared with the group M.2)HE staining of liver:Compared with group C,the structure of liver was disorderd in group M,and liver cells were arranged in disorder,liver cells were filled with the size of fat vacuoles.In group T,the liver cells were less swollen and fat vacuoles,the liver cells arranged more neatly.5 Alteration of Intestinal tissue1)HE staining of intestinal tissue:Intestinal villis were arranged closely in group C.In group M,the intestinal villis became short,sparse,partial lossing.Compared with group M,the intestinal villus of group T was edema mildly,arranged more neatly.2)Scanning electron microscopy observation of intestinal mucosa:Intestinal villis of rats in group C were heavy leaf shaped,spaced closely,fractures in the surface were varying shades,high magnification showed that intestinal microvillis were dense,arranged in neat rows.The intestinal villis in group M was flat,arranged sparsely,cracks in the surface of villous were darker,at high magnification,the microvillis were sparse,between them there were large gaps.Compared with group M,the testinal villis were plump and arranged tightly,intestinal microvillis arranged with regular,gaps between them was smaller.Conclusions:1 High fat diets can induce NAFLD in rats,and there is impairment of intestinal mucosal barrier function in NAFLD rats.2 FMT can improve the function of intestinal mucosal mechanical barrier and reduce the permeability of intestine in NAFLD rats.3 FMT can reduce the level of endotoxin in NAFLD rats.4 FMT can reduce body weight,the level of blood lipid,hepatic steatosis and improve the liver function in NAFLD rats.