The Mucosal Microbiota Analysis Of Ulcerative Colitis And Colorectal Adenoma And Its Correlation Studies

Background:Ulcerative colitis and colorectal adenomas are currently common diseases that not only cause uncomfortable symptoms but may also lead to canceration.And these two diseases are easy to relapse.In addition to the genes,some controllable factors should be explored to reduce the incidence or change the outcome of the disease.There is a complex and huge microbial community in the human gastrointestinal tract,called a microbiota.To date,it is known that the microbiota in the intestine have many benefits to the human body,including immune regulation,nutrient utilization,and provision of a protective intestinal barrier.However,if the "disease dysbacteriosis" interferes with the intestinal microflora,obesity,antibiotic-associated diarrhea,autism,irritable bowel syndrome,inflammatory bowel disease and other diseases may occur.The interaction of disease states with dysbacteriosis often leads to more serious diseases.It is well known that human microbiota is inherently dynamic,but the dynamics of the microbiota are still our secret.Understanding the dynamic changes of the microbiota from a physiological state to a morbid state is very important because it helps to guide how to effectively regulate the gut microbiota.We know that about 1014 bacteria are present in the human gut.In such a closed community,members must compete strongly to obtain the limited energy source from mucin and food.The microbiota and the physiological state of the host maintain a balance under normal conditions.The goblet cells of the gut epithelium secrete mucopolysaccharides to support mucosal-associated microbiota,and the amount and composition of mucus procduced by goblet cells depends on the local signal of the gut microbiota and itself.Microbiota can provide beneficial nutrient signals to the host,and may also provide unfavorable signals that become a risk factor for the disease.Therefore,the diversity and complexity of the microbiota and its formation affect the intestinal homeostasis and disease state.At the same time,host physiology may have a strong influence on the dynamics of the intestinal microbiota.Changes in mucosal physiology,such as inflammation,will produce oxides that act as additional electron acceptors and cause facultative anaerobic growth.It was found that in the colorectum the density and function of epithelial goblet cells always become lower if there is colitis or adenoma lesions.So,host physiological changes can lead to the destruction of mucosal barrier function and intestinal microbial imbalance,called dysbacteriosis,which may cause pathological changes.However,we still have little insight into the changes and differences in microorganisms under different pathophysiological conditions.Many studies need to be completed.In recent years,the study of microbiota has been widely applied to the study of pathogenesis,and the number of documents of various microbial groups has also rapidly increased.It is well-known that Helicobacter pylori is closely related to peptic ulcer and in IBS there is intestinal bacteria proliferate.However,because the evidence is mainly based on breath test or fecal test,the debate has continued for a long time.The 16S rDNA high-throughput results show that there are many quantitative and qualitative changes between the mucosal and fecal intestinal microbiota.In order to perform these tasks,we need a tool to evaluate the epithelial physiology in vivo.Confocal laser endoscopy is a new and useful gastrointestinal technique that can provide us with mucosal histological images and evaluate epithelial physiology in real time.Using CLE,many endoscopic physicians can evaluate the condition of the intestinal mucosa,such as epithelial integrity,inflammatory extrusion and angiogenesis.A number of studies have shown that the sensibility,accuracy and specificity of diagnosis of ulcerative colitis and colorectal adenoma by CLE are high.We can then use CLE to evaluate epithelial physiology and perform targeted biopsy in vivo because CLE can provide us with in situ and non-invasive observations and then sequence and quantificat the microbiota on targeted mucosa.The CLE technology is making progress.At present,the probe-based confocal laser endomicroscopy(pCLE)provides easier operation and can be carefully rewinded.We will use pCLE with 16S rDNA high-throughput sequencing to perform the endoscopic diagnosis in vivo and sequence the mucosal microbiota respectively.Next we will cluster the OTU,construct evolution trees,and take a variety of test methods and SVM to perform correlation analysis.Objectives:To observe what changes presented and the differences about the mucosal microbiota when it was in various pathological conditions and different biopsy sites.To discuss whether the mucosal microbiota has diagnostic value.Methods:In the Endoscopic Unit of Qilu Hospital,patients who required colonoscopy between November 2013 and July 2017 participated in the study.For each patient,standard high-resolution colonoscopy was first performed by an experienced endoscopic physicians.If lesions were observed,the patients met the inclusion criteria and then pCLE was used to assess the physiological status of the human colorectal mucosa at the site of lesions and normal control mucosa,and endoscopic diagnosis was performed.The targeted biopsies were taken,treated and kept properly.Sequenced the mucosal microbiota by means of 16s rDNA High-throughput sequencing.Next the processed sequencing data was analyzed and clustered with mothur.We compared the differences of mucosal microbiota between different diseases and different segments with multiple test methods,constructed the evolution trees and analyzed them At last we evaluated the diagnostic value of mucosal microbiota.Results:In this study,771 patients underwent colonoscopy,and finally 78 patients were involved in follow-up studies.A total of 1,992,098 reads of high quality were obtained.The 8,151 OTUs were gotten according 0.97 similarity.According to the difference analysis,we found that both biopsy site and disease type could impact the composition of mucosal microbiota,the former was greater.We constructed the overall evolution diagrams of 16s rDNA genes.The evolution diagrams show the evolution relationship between microbiota.Every small branch presents a OTU.The closer the end says the closer relationship.The 16s rDNA genes of mucosal microbiota had potential diagnostic value.Conclusions:Confocal laser endomicroscopy is a very useful tool for assessing pathophysiological conditions of mucosa,making early diagnosis and taking targeted biopsy.Both biopsy site and disease type could impact the composition of mucosal microbiota.The 16s rDNA genes of mucosal microbiota had potential diagnostic value.