Study On The Protective Effect And Mechanism Of Bacillus Coagulans LT3 On LPS-induced Acute Liver Injury In Rats

Research background: Bacillus coagulans is a probiotic widely used in animal production,which plays a certain role in the body’s nutrient absorption,immune response,and anti-infection,thereby greatly improving animal production performance.With the social understanding of the harm of the abuse of antibiotics and the in-depth study of the influence mechanism of Bacillus coagulans and its compound bacteria on the body,adding Bacillus coagulans to feed instead of part of antibiotics will become the future development trend,and Bacillus coagulans will be widely used in the breeding industry.Objective: The main purpose of this study was to investigate the protective effect and mechanism of Bacillus coagulans LT3 on LPS-induced acute liver injury.The experimental results will lay a theoretical foundation for the application of Bacillus coagulans in actual aquaculture production.Methods: In this experiment,48 male SPF Wistar rats(body weight 180±10 g)were selected and randomly divided into six groups: group C(blank control group,gavage with sterile LB medium),group B Group(high concentration Bacillus coagulans group),LPS group(LPS toxin group,gavage with sterile LB medium),H group(high concentration Bacillus coagulans + LPS group),M group(medium concentration Bacillus coagulans + LPS group)),L group(low concentration of Bacillus coagulans + LPS group),fed for two weeks and recorded daily body weight,fasted for 12 hours on the fifteenth day,LPS group,H group,M group,L group of rats in the abdominal cavity LPS(1 mg/kg body weight)was injected,and the rats in group C and group B were intraperitoneally injected with normal saline.After4 h,all rats were anesthetized,sacrificed by cervical dislocation,and blood and liver samples were collected.The weight changes and liver organ coefficients of the rats in each group were calculated and the growth curve was drawn;the histopathological changes of the rat liver were observed by HE staining and transmission electron microscope;the contents of ALT and AST in serum and liver were detected to determine the liver function;The content of MDA,NO and SOD,CAT activities in liver were used to determine the changes of anti-oxidative stress in liver;The protein and gene m RNA expressions of oxidative stress pathways Nrf2,NQO1,HO-1,inflammatory pathways NFκB,TNF-ɑ,and IL-1β in liver were detected by WB and q PCR.Results:(1)Feeding LT3 improved the production performance of rats and protected the liver.(2)Feeding LT3 relieved LPS-induced damage of serum enzymes and liver function in rats.(3)In the results of HE staining and transmission electron microscopy of rat livers,LT3 greatly alleviated liver degeneration and inflammatory cell infiltration caused by LPS,indicating that feeding LT3 has a protective effect on LPS-induced liver injury in rats.(4)Feeding Bacillus coagulans LT3 alleviated the increase of MDA and NO content in LPS-induced rat liver,inhibited the decrease of SOD and CAT activity,and thus played a protective effect on LPS-induced oxidative damage of rat liver.(5)WB and q PCR analysis showed that LPS-induced oxidative stress pathways Nrf2,NQO1,HO-1 and inflammatory pathways NFκB,TNF-ɑ,IL-1β protein and gene m RNA expression increased high,LT3 inhibited the occurrence of this phenomenon,and the results indicated that LT3 played a protective role against LPS-induced oxidative stress and inflammation.Conclusion: Bacillus coagulans LT3 can alleviate the acute injury of LPS-induced liver injury in rats by inhibiting oxidative stress and inflammatory pathways in a dose-dependent manner.