| The intestinal microbiota of livestock and poultry is a huge and complex ecosystem,which accounts for about 80%of total bacterial flora in the whole body.The breeding process of livestock and poultry is a delicate one,it is constantly challenged by various factors such as poor feeding environment,unreasonable feed structure and drug stress.These factors not only affect normal growth,but also the metabolism of intestinal microbiota leading to imbalances of intestinal microbiota,and subsequently threaten animal health.More studies have shown that most effects of intestinal microbiota on animal physiology are related to microbial metabolites,which are key mediators of diet based physiological processes.Intestinal microbiota,mucus,intestinal epithelial cells and submucosal immune cells constitute the intestinal mucosal barrier.There is interaction between intestinal microbiota,intestinal mucosal barrier and intestinal innate immunity.As a new type of probiotic,Akkermansia muciniphila(A.muciniphila)has a significant effect in improving metabolism and reducing obesity.At present,studies have also found that A.muciniphila can enhance the intestinal mucosal barrier through its membrane proteins and extracellular vesicles,but its mechanism is still not very clear.With the development of metabonomics technology,there are better technical means to explore the role of intestinal microbiota and its bioactive metabolites in enhancing intestinal mucosal barrier and improving intestinal inflammation in livestock and poultry.This experiment is to explore in order to better apply probiotics as the core of microecological products in production practice.1 Based on metabolomics to explore the changes of animal intestinal metabolites after feeding Akkermansia muciniphilaIn our previous research,we found that A.muciniphila can alleviate the intestinal inflammation induced by DSS by regulating the balance of innate immune cells Treg/Th17.In order to further explore the mechanism of A.muciniphila alleviating intestinal inflammation,we used non-Targeted metabolomics technology detection on four samples each in the blank control group and A.muciniphila group.PCA analysis found that compared with the blank control group,the overall distribution trend variability was bigger,and the model was accurate,stable and reliable.Through the screening and analysis of differential metabolites,we found that a total of 15 kind of metabolites in the positive channel were significantly up-regulated,15 kind of metabolites were significantly down-regulated,a total of 15 kind of metabolites in the negative channel were significantly up-regulated,and 17 kind of metabolites were significantly down-regulated.Through Cluster analysis and KEGG Pathway analysis we found that these differential metabolites are related to Purine metabolism and the changes in the metabolite phloretin are significantly up-regulated in both cation channels and anion channels,laying the foundation for us to further explore the effects of phloretin.2 Study on the mechanism of metabolite of Akkermansia muciniphila—Phloretin enhances the intestinal mucosal barrier of chicksIn order to explore the effects of phloretin,which is characterized as A.muciniphila metabolite,on the intestinal mucosal barrier of white-feather broilers,in this study we used 100 μg/g of phloretin in drinking water to feed 1-day-old white-feather broilers.HE staining results,crypt depth and lipopolysaccharide detection results were used to determine the effect of phloretin on growth promotion and intestinal health of white feather broilers;and to explore its mechanism in maintenance of intestinal health through PAS staining and intestinal mucosal barrier related gene detection.The research results showed that phloretin could significantly increase body weight,improve anatomical morphological indicators,and could significantly increase the depth of crypts and reduce the level of lipopolysaccharide endotoxin;in this study,we also found that phloretin could increase the goblet cells in the intestinal tract of white-feather broilers,the expression of mucin-related genes Muc2 and Tff2 in the intestine were significantly up-regulated,and aryl hydrocarbon receptors were highly expressed at the gene level to promote the production of IL-22 in vivo and promote the proliferation of intestinal epithelial cells.The above results indicates that phloretin,a metabolite of A.muciniphila,promoted the proliferation of intestinal epithelial cells and enhanced the intestinal mucosal barrier by inducing IL-22 secretion and regulating the Wnt signaling pathway,thereby ensuring the intestinal health of white feather broilers.3 Study on the mechanism of phloretin enhancing intestinal mucosal barrier and relieving intestinal inflammation in miceIn order to further explore the role of phloretin in protecting the intestinal mucosal barrier and alleviating intestinal inflammation in animals,in this experiment we selected male five-week-old C57BL/6 mice as subjects,and continuously gavage 100 μg/g phloretin for 14 days.On the 7th day of the experiment 3.5%DSS was put with drinking water to establish an intestinal inflammation model.Under the effect of 3.5%DSS,the weight of the mice decreased significantly,the length of the colon was significantly shortened,and the pathological section showed that the mouse colon lost the normal tissue morphology.ELISA detected the content of inflammatory factors in the colon,and we found the content of the inflammatory factor interleukin 1β in the colon was significantly increased.The phloretin treatment could effectively protect the intestine from DSS-induced intestinal inflammation,which was reflected in indicators such as body weight,colon pathological morphology,colon tissue morphology,and inflammatory factors.The above results proved that phloretin can relieve DSS-induced intestinal inflammation and protect the intestinal mucosal barrier of mice.Phloretin could protect the intestinal mucosal barrier and relieve the intestinal inflammation induced by DSS,but its underlying mechanism is still unclear.As the mucosal barrier of the intestine is closely related to mucus secretion,we tested the goblet cells which was related to mucus secretion and found that the goblet cells increased significantly in the repaired group.Secondly,the expression of genes related to IL-22 and STAT3 pathways was also significantly up-regulated.ELISA detection of the cytokine IL-22 secreted by the intestines was consistent with the gene expression level.After the treatment of phloretin,the secretion of IL-22 in the colon increased significantly.Immunohistochemistry detected that the level of STAT3 was significantly activated after the phloretin treatment,and the Western blot results remained consistent.The above results indicates that phloretin,a metabolite of A.muciniphila stimulates the secretion of IL-22 by intestinal immune cells by up-regulating aryl hydrocarbon receptor expression to further activate the STAT3 signaling pathway,improve DSS-induced intestinal inflammation,and protect the intestinal mucosal barrier function.4 Study on the mechanism of Akkermansia muciniphila protects the intestinal mucosa from Salmonella pullorum by initiating the proliferation of the intestinal epitheliumIn order to explore the role of A.muciniphila in resisting the invasion of intestinal pathogens and in the entire chick’s intestinal mucosal barrier repairment,we further used A.muciniphila as a whole to treat chickens.The study found that A.muciniphila could colonize in the intestines,alleviated the intestinal mucosal damage of chicks caused by Salmonella pullorum(S.pullorum),and improve weight loss and intestinal inflammation.The repair process activated by A.muciniphila is accompanied by an increase in the number of goblet cells in the intestine of the chick and the up-regulation of Muc2 and Tff2.In addition,A.muciniphila also increased proliferating cell nuclear antigen and accelerated the proliferation of intestinal epithelium by regulating the Wnt signaling pathway,thereby restoring the intestinal mucosa damaged by S.pullorum.This study confirmed that the metabolite of A.muciniphila—phloretin can enhance the intestinal mucosal barrier of chicks,and A.muciniphila can promote the proliferation of intestinal epithelium and resist the infection of S.pullorum.It is phloretin and mucophila.It provides a theoretical basis for the application of phloretin and A.muciniphila in the prevention and treatment of diarrhea in poultry farming. |
PDF Full Text Request