替吉奥与肠道微生态失衡之间的关系以及益生菌对失衡的修复作用

发布时间：2018-05-07 21:58

本文选题：替吉奥 + 肠道菌群　；参考：《大连医科大学》2014年硕士论文

【摘要】：替吉奥是一种新型氟尿嘧啶类口服抗癌药物是抗肿瘤药替加氟的一种改进型制剂，是替加氟、吉美嘧啶、奥替拉西按照摩尔比1：0.4：1组成的复方制剂[1-3]。用于晚期胃癌的一线治疗以及进行性或复发性头颈部肿瘤、进行性或复发性结肠直肠癌、进行性非小细胞肺癌、转移性乳腺癌、转移性胰腺癌和胆管癌等的治疗[4]，据统计日本晚期胃癌的治疗，有80%以上的病例使用替吉奥，治疗有效率（CR+PR）可达44.6%。替吉奥中奥特拉西能够降低5-氟尿嘧啶在肠组织内产生磷酸化(磷酸化的结果是导致胃肠道不良反应的主要原因)，但其胃肠反应仍然不容忽视，多表现为便秘、腹泻及胃肠道出血，加重患者的痛苦，不利于病情的好转。微生态学是一门研究生物体正常微生物群与其宿主相互依赖、相互制约规律的科学。我国著名微生态学专家康白教授将微生态系统的定义为：微生态系统是指在一定结构的空间内，正常微生物群以其宿主的组织和细胞及其代谢产物为环境，在长期的进化过程中形成的能独立进行物质、能量及信息相互交流的统一的生物系统。肠道微生态是人体最大的微生态系统，被认为是人体一个重要的器官，参与人体的新陈代谢，对人体健康起着至关重要的作用。肠道菌群处于健康状态时，维持着人体的的各种功能，其机制可总结为以下几点：营养促进作用、参与肠粘膜的增生、免疫作用等。当肠道菌群失衡时，致病菌就会大量滋生，导致肠粘膜粗糙、血液流通不畅、产生大量有害物质、胃肠蠕动异常以及导致病原体的侵入。现已证明肠道菌群失衡与肥胖、高血脂、胃炎、癌症等多种疾病有关。近一个世纪来，人们对益生菌的研究越来越多，越来越深入，研究发现益生菌对人体健康有益。益生菌能够产生β-半乳糖苷酶催化乳糖分解，减轻乳糖不耐症，还能促进蛋白质和钙等营养物质的吸收，部分益生菌能够合成维生素B12和叶酸，起到营养机体的作用。益生菌在繁殖过程中产生大量的有机酸，刺激肠壁蠕动，增加胃动力。另外益生菌定植后，能够在肠粘膜上形成一层保护膜，，起到屏障作用，拮抗致病菌。益生菌能够产生细菌素、抗生素及其他代谢物、空间争夺等抑制致病菌的增值，维持肠道微生态的平衡，保持宿主正常的营养、免疫、消化等生理功能[5]。对于肠道菌群的检测有多种方法，依靠体外培养的技术例如细菌涂片是最直接、最简单、快速的经典方法，区分革兰氏阳性菌与革兰氏阴性菌的比例，可以初步判断肠道菌群是否失衡；还有细菌培养法，它是一种定量的细菌培养法。虽然体外培养技术简单易操作，但可培养细菌的比例与肠道微生态细菌总量相比，存在较大差异，因为很多细菌无法实现体外培养，可培养的细菌只占总数的30%-40%，无法完全反应肠道菌群的组成，而且体外培养环境与肠道环境不能完全相同加之人为操作因素，也可能会改变原有的微生物群落，随着科技的发展分子生物技术开始应用于肠道菌群的检测，rRNA分子在生物进化过程中始终保持相对恒定的生物学功能和保守的碱基排列序列，同时也存在为保守区和可变区，研究rRNA基因序列可以发现各物种间的体统发生关系，其中16sRNA长度约1540bp，较易于进行序列的测定，近年来以16sRNA为基础的分子生物学技术开始应用于肠道微生态的分析，包括实时定量PCR、荧光原位杂交、核酸探针技术、TGGE、PCR-DGGE、TGGE、T-RFLP等[6]。其中PCR-DGGE对菌群种属进行定性、半定量分析，其优点是可将相同长度不同序列的PCR扩增片段进行分离，检测率高、重复性好。DGGE图谱中，条带比较粗亮说明细菌密度大，条带细浅则菌密度小，另外DGGE图谱中条带的数量也体现的肠道菌群的种群数量，因此在后面对DGGE图谱的分析中我们也会利用相应软件分析条带的灰度值及数量[7]。本实验用357F-GC／518R引物扩增16S rDNA的V3可变区,基于16S rRNA基因的聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术应用于肠道微生态学，对DGGE指纹图谱进行相似性、多样性分析及优势条带的序列分析，检测替吉奥对人体肠道菌群的影响，以及两歧双歧杆菌、嗜酸乳杆菌、婴儿双歧杆菌组成的益生菌制剂能否修复由替吉奥引起的肠道菌群失衡,为临床合理用药提供参考。
[Abstract]:Tegio is a new type of oral anticancer drug, a new type of antitumor drug tegafur. It is a first-line treatment of advanced gastric cancer and progressive or recurrent head and neck tumors by [1-3]., a compound preparation of tegafur, gimilacil, and oretirine, based on the mole ratio 1:0.4:1, with progressive or recurrent head and neck tumors. Colorectal cancer, progressive non-small cell lung cancer, metastatic breast cancer, metastatic pancreatic cancer and cholangiocarcinoma are treated with [4]. According to the treatment of advanced gastric cancer in Japan, more than 80% of the cases were used as teggio, and the therapeutic efficiency (CR+PR) could reach 44.6%. teggio in oteasi can reduce the phosphorylation of 5- fluorouracil in the intestinal tissue (phosphorus) The result of acidification is the main cause of the adverse reaction of the gastrointestinal tract, but the gastrointestinal reaction still can not be ignored. It is often manifested in constipation, diarrhea and gastrointestinal bleeding, which aggravates the suffering of the patients and is not conducive to the improvement of the condition.
Microbiology is a science that studies the mutual dependence and restriction of the normal microorganism group and its host. Professor Kang Bai, a famous microecology expert in China, defines the microecosystem as: the microecological system refers to the tissues and cells and their metabolites of the normal microorganism in a certain structure. For the environment, a unified biological system is formed in the process of long-term evolution, which can independently carry out material, energy and information. The intestinal microecology is the largest microecosystem in the human body. It is considered to be an important organ of the human body. It plays a vital role in human body health. In a healthy state, it maintains various functions of the human body. Its mechanism can be summarized as following: nutrition promotion, participation in intestinal mucosa hyperplasia, immune function and so on. When the intestinal flora is unbalanced, the pathogenic bacteria will grow in large numbers, causing the rough intestinal mucosa, poor circulation of blood, producing a large number of harmful substances, abnormal gastrointestinal peristalsis and causing disease. The invasion of cancer has proved that intestinal flora imbalance is related to obesity, hyperlipidemia, gastritis, cancer and many other diseases.
In the past century, more and more studies have been made on probiotics. Research has found that probiotics are beneficial to human health. Probiotics can produce beta galactosidase to catalyze lactose decomposition, reduce lactose intolerance, and promote the absorption of nutrients such as protein and calcium. Some probiotics can synthesize vitamin B12 and folic acid. Probiotics produce a large amount of organic acids in the breeding process, stimulate the peristalsis of the intestinal wall, and increase the motility of the stomach. In addition, probiotics can form a protective membrane on the intestinal mucosa after probiotic colonization. It can act as a barrier and antagonize pathogenic bacteria. Probiotics can produce bacterial, antibiotics and other metabolites, space contention and so on. The increment of pathogenic bacteria can maintain the balance of intestinal microecology and maintain the normal physiological functions such as nutrition, immunity and digestion of the host. [5].
There are many methods for the detection of intestinal flora. In vitro culture, such as bacterial smear is the most direct, simplest and fast classical method to distinguish the proportion of Gram-positive bacteria and Gram-negative bacteria, it can preliminarily judge whether the intestinal flora is unbalance, and the bacterial culture method is a quantitative bacterial culture method. In vitro culture technology is simple and easy to operate, but the proportion of the bacteria can be compared with the total amount of intestinal microecological bacteria, because many bacteria can not be cultured in vitro. The bacteria can only account for 30%-40% of the total number of bacteria, which can not fully reflect the composition of intestinal flora, and the culture environment in vitro and the intestinal environment can not be exactly the same. In addition to human manipulation factors, it may also change the original microbial community. With the development of technology, molecular biotechnology has been applied to the detection of intestinal microflora. RRNA has maintained relatively constant biological function and conservative sequence sequence throughout the process of biological evolution, and also exists as a conservative area and variable region, and studies rR NA gene sequence can find the relationship between species, in which the length of 16sRNA is about 1540bp, and it is easier to determine the sequence. In recent years, the molecular biology technology based on 16sRNA has been applied to the analysis of intestinal microecology, including real-time quantitative PCR, fluorescence in situ hybridization, nucleic acid probe technology, TGGE, PCR-DGGE, TGGE, T-RFLP and so on. In 6]., PCR-DGGE was qualitative and semi quantitative analysis. The advantage was that the PCR amplification fragments of the same length and different sequences could be separated, the detection rate was high and the reproducibility good.DGGE atlas. The strip was bright and bright indicating that the density of bacteria was large, the strip was small and the density of the bacteria was small. In addition, the number of bands in the DGGE map also reflected the intestinal bacteria The number of groups, so in the subsequent analysis of the DGGE map, we will also use the corresponding software to analyze the gray value and the number of bands [7].
In this experiment, the V3 variable region of 16S rDNA was amplified with 357F-GC / 518R primers, and the polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) based on 16S rRNA gene was applied to the intestinal microecology. The similarity, diversity analysis and sequence analysis of the dominant bands were used to detect the shadow of the intestinal flora of the human body. Whether or not the probiotics of Bifidobacterium bifidus, Lactobacillus acidophilus and Bifidobacterium infantile can repair the imbalance of intestinal flora caused by tegio, and provide a reference for clinical rational use.

【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R96

【参考文献】