植物与昆虫之间全方位的“军备竞赛”使得彼此之间的防御反应和反防御反应逐级递进，近年来越来越多的研究发现昆虫共生微生物也参与其中。昆虫肠道是共生微生物着生的最重要场所之一，也是植食性昆虫与寄主植物互作的关键界面。肠道微生物在植食性昆虫及其寄主植物互作过程中的作用是多方面的。首先，肠道微生物可以为植食性昆虫合成寄主植物不能提供或者提供量不足的营养成分；其次，肠道微生物协助昆虫应对寄主植物防御反应，比如操纵植物的防御信号转导和降解抗虫次生代谢产物等；最后，肠道微生物在植食性昆虫、寄主植物与昆虫天敌三级营养关系中也发挥着重要作用。本文综述了植物与昆虫二者之间的“攻防”互作机制，在此基础上重点探讨了肠道微生物在昆虫适应寄主植物防御方面的作用，展望了肠道微生物的研究方法及其在害虫综合防治中的应用前景。

The evolutionary arms race between plants and herbivorous insects is a complex process that has developed multiple facets over time. Recent studies have increasingly highlighted the role of symbiotic microorganisms in this dynamic co-evolutionary contest. The insect gut serves as a crucial interface for herbivore-plant interactions, and is also the primary habitat for symbiotic microorganisms. These microorganisms influence plant-insect interactions on several levels. First, they can provide essential nutrients that plants may not provide to herbivores. Second, insects often rely on these symbionts to cope with the defensive strategies of their host plants, including the manipulation of defense signaling pathways and the detoxification of harmful compounds. Finally, gut microbes play a significant role in tritrophic interactions between host plants, herbivorous insects and natural enemies. In this article, we review the arms race between plants and insects and emphasize how gut microorganisms help insects counter plant defenses. Furthermore, we discuss cutting-edge methodologies employed to study insect-symbiont interactions and explore the potential applications of gut microbiome research in integrated pest management.