动物肠道菌群与病原微生物感染关系的研究进展

Research Progress on the Relationship Between Gut Microbiota of Animals and Pathogenic Microorganism Infection

动物肠道内寄居着大量微生物,通常被称为共生菌群。它们对动物的生长、代谢和免疫状态至关重要,还与许多疾病的发生密切相关。病毒、细菌和寄生虫感染都会使机体的肠道菌群发生紊乱,表现在益生菌丰度减少而有害菌丰度增加。其机制包括引发宿主的炎症反应和抑制机体的免疫细胞两方面。同样肠道菌群也会调控病原菌的感染,如肠道菌群对不同的病毒会产生颉颃或促进作用,对细菌和寄生虫分别产生抑制和促进作用。肠道菌群抑制病原菌的机制包括与病原菌竞争代谢产物和诱导宿主的免疫反应。肠道菌群促进病毒感染的机制包括3点,分别为提高病毒的稳定性及其与靶细胞的黏附作用、抑制机体免疫系统和刺激靶细胞的增殖。肠道菌群促进寄生虫感染的可能机制包括降低Th2细胞因子(如IL-4和IL-13)并提高调节性T细胞的表达频率。肠道菌群、病原微生物和宿主不断相互作用,形成一个动态的平衡关系,并在感染过程中不断进化。作者主要综述了病毒、细菌和寄生虫感染对动物肠道菌群的组成和丰度的影响,动物肠道菌群如何影响病毒、细菌和寄生虫的感染进程并分析相关机制,以期了解疾病的发病机理,为疫苗佐剂的研发及制定更有效的预防和治疗策略提供新视角和理论依据。

Animals harbor a densely populated resident microbial community,generally referred as the commensal microbioata,which are pivotal in determining the developmental,metabolic and immunological status of the host.They are active participants in the progression of many diseases.The invasion of viruses,bacteria and parasites result in a disturbance to the gut microbiota,mainly is shown by a decrease of probiotics,while outgrowth of pathogens.The mechanisms include eliciting inflammatory host response and inhibiting immune cell.Additionally,gut microbiota also accommodate pathogenic organisms.For example,it plays a dual role in viral replication,inhibits bacterial replication,but promotes parasite infection.The mechanisms that regulate the ability of the gut microbiaota to restrain pathogen growth including competive metabolic interactions and induction of host immune responses.And the mechanisms of viral promoting involved are listed as follow:Improving the stability of virus and enhancing their attachment to target cells,inhibiting the immune system,promoting the proliferation of target cells.The mechanisms of parasite promoting maybe decrease Th2 cytokines (such as IL-4 and IL-13),as well as with heightening the frequency expression of regulatory T cell.The interactions among gut microbiota,pathogen and host affect are ongoing and continuously evolving throughout the infection process.This review focused on the impact of viruses,bacteria and parasites on the abundance of animals’ gut microbiota,the process of pathogen infection impacted by animals’ gut microbiota and the relevant mechanism.A goal of this work will facilitate our understanding of the mechanism of infection.What’s more,it can also provide novel insights and theory for developing vaccines adjuvants and designing more effective and focused prophylactic and therapeutic strategies.