肠道菌群影响阿片类成瘾行为的分子模拟机制及其人参皂苷抗成瘾的菌群重塑研究

Gut microbiota can cross-talk with CNS by the gut-brain axis and plays an important role in many neuropsychiatric disorders. The previous studies in our research group found that morphine abuse could lead to gut microbiota disorder in mice, resulting in behavioral phenotype and molecular phenotype changes that were similar to those of the host. It is speculated that gut microbiota can produce a co-metabolism with host by molecular mimicry mechanism, resulting in co-addiction with host. Drug addiction can occur outside the CNS, and the gut microbiota has an important role on the consolidation and maintenance of addiction. Ginsenosides can interfere with opioid addiction and has a remolding effect on the disordered gut microbiota. The study on gut microbiota will reveal and elucidate the mechanism of drug addiction from different from traditional notes and find new targets of traditional Chinese Medicine treating addiction. This project will be based on the gut microbiota as the pointcuts, and study the variation characteristics of the gut microbiota and its effects on addictive behavior via the morphine dependence model in mice, by the aid of 16S RNA gene sequencing technology, miRNA chip technology and microbial detection method. this project will also study the remolding mechanism of ginsenoside on the disordered gut microbiota. It will elucidate the molecular mimicry mechanism of gut microbiota and its interaction with CNS. The project introduces innovatively gut microbiota to the fields of drug addiction and traditional Chinese medicine, open up a new pathway of Chinese Medicine - gut microbiota application.

肠道菌群经肠-脑轴与CNS进行双向交流，并在多种神经精神系统疾病中发挥重要作用。本项目组前期研究发现，吗啡滥用可导致小鼠肠道菌群紊乱，产生与宿主相似的行为表型和分子表型变化。推测肠道菌群通过分子模拟机制与宿主共代谢产生两者共成瘾。药物成瘾可以发生在CNS之外，肠道菌群对成瘾性的巩固与维持有重要影响。人参皂苷在对阿片类成瘾干预的同时，对紊乱的菌群有重塑作用。对肠道菌群的研究，可从一个全新的角度注释和阐明药物成瘾机制，从中发现中药作用的新靶标。本项目以肠道菌群为切入点，通过吗啡依赖小鼠模型，借助16SrRNA基因测序技术、miRNA芯片技术、微生物检测等方法，研究成瘾状态下小鼠肠道菌群的变化特征及其对成瘾行为的影响，同时研究人参皂苷对肠道菌群的重塑机制，阐明肠道菌群的分子模拟机制及其与CNS的相互调控作用。本项目创新性地把肠道菌群引入毒瘾医学和中药学领域中，开拓了中药-肠道菌群应用新途径。

肠道菌群是研究中医理论及中药药效机制的重要突破口。本项目以肠道菌群为主题进行中药抗药物成瘾研究。研究内容有6个方面：1.吗啡依赖CPP小鼠行为学和肠道菌群生物特征及人参皂苷的抗成瘾机制；2.肠道菌群减少型吗啡依赖小鼠的肠道菌群机制及人参皂苷的干预效应；3.普通拟杆菌及粪菌移植对吗啡依赖小鼠的影响及人参皂苷的肠道作用机制；4.吗啡通过宿主miRNA塑造肠道细菌成瘾表型及人参皂苷对菌群的重塑作用；5.菌群相关的肠道动力学研究及人参皂苷对肠道运动的影响；6.基于斑马鱼模型研究吗啡依赖斑马鱼肠道菌群生物特征及中药抗吗啡成瘾的相关机制。研究结果表明，吗啡依赖可导致小鼠肠道菌群的组成和多样性发生改变，普通拟杆菌明显减少，并能改变宿主粪便和血清代谢物水平。人参皂苷Rg1能明显抑制吗啡依赖小鼠CPP效应，同时改变成瘾小鼠的肠道菌群特征并增加肠道拟杆菌的丰度，降低肠道色氨酸和血清5-HT含量。推测人参皂苷可通过改变肠道菌群，调节色氨酸代谢，抑制5-HT途径产生抗成瘾作用。肠道不吸收抗生素的使用导致小鼠肠道菌群明显减少，呈肠道菌群失调现象，使小鼠对吗啡的敏感性增高，同时也使人参皂苷Rg1的抗吗啡依赖作用减弱，表明吗啡成瘾及人参皂苷的作用均与肠道菌群密切相关。普通拟杆菌的使用可增加小鼠肠道中拟杆菌门的丰度，增强人参皂苷Rg1对吗啡依赖的抑制作用。本研究发现，吗啡依赖可致肠道及大脑miRNA表达谱改变,宿主miRNA能明显影响肠道细菌的生长，呈现与成瘾小鼠的菌群丰度一致的生长曲线，表明吗啡通过宿主miRNA完成对菌群成瘾表型的塑造。人参皂苷可通过对肠道菌群的调节和对细菌表型的重塑发挥作用。人参皂苷对吗啡依赖的肠道运动有明显调节作用。吗啡依赖也可引起斑马鱼肠道菌群的生物特征发生改变，中药可通过调节肠道菌群发挥抗药物依赖作用。本项目研究揭示了肠道菌群对药物成瘾的影响，为中医药防治药物依赖提供新的途径。