In recent years, an increasing number of studies have reported that intestinal microbiota have an important effect on tumour immunity by affecting the tumour microenvironment (TME). The intestinal microbiota are closely associated with various immune cells, such as T lymphocytes, natural killer cells (NK cells) and macrophages. Some bacteria, such as Akkermansia muciniphila (A. muciniphila) and Lactobacillus reuteri (L. reuteri), have been shown to improve the effect of tumour immunity. Furthermore, microbial imbalance, such as the increased abundance of Fusobacterium nucleatum (F. nucleatum) and Helicobacter hepaticus (H. hepaticus), generally causes tumour formation and progression. In addition, some microbiota also play important roles in tumour immunotherapy, especially PD-L1-related therapies. Therefore, what is the relationship between these processes and how do they affect each other? In this review, we summarize the interactions and corresponding mechanisms among the intestinal microbiota, immune system and TME to facilitate the research and development of new targeted drugs and provide new approaches to tumour therapy.

中文翻译：

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肿瘤微环境中肠道菌群与肿瘤免疫的相互作用

近年来，越来越多的研究报道肠道菌群通过影响肿瘤微环境（TME）对肿瘤免疫产生重要影响。肠道菌群与多种免疫细胞密切相关，如T淋巴细胞、自然杀伤细胞（NK细胞）和巨噬细胞。某些细菌，例如Akkermansia muciniphila（A。muciniphila）和罗伊氏乳杆菌（L。杆菌），已经显示出改善的肿瘤免疫的效果。此外，微生物不平衡，如丰度的增加的具核梭杆菌（F。具核）和肝螺杆菌（H。肝螺杆），通常会导致肿瘤的形成和进展。此外，一些微生物群在肿瘤免疫治疗，尤其是 PD-L1 相关治疗中也发挥着重要作用。因此，这些过程之间是什么关系，它们又是如何相互影响的？在这篇综述中，我们总结了肠道菌群、免疫系统和 TME 之间的相互作用和相应机制，以促进新靶向药物的研发并为肿瘤治疗提供新方法。