人类与大量细菌、真菌和病毒共同生存、进化了数百万年，已初步从分子水平了解了极少数特定细菌与癌症之间的病原学关系。随着二代测序技术的逐步成熟，将进一步推动对微生物尤其是肠道细菌的深入研究，从而解析细菌与癌症之间的分类学和代谢组学关系。本文主要综述了肿瘤组织及其周边微环境中的细菌以直接和（或）免疫调节方式介导肿瘤发生发展的机制。

For millions of years, human beings have coexisted and coevolved with a vast number of bacteria, fungi and viruses. Now, the epidemiological relationships between several specific bacteria and cancer are explored at the molecular level. With the increasing maturity of next-generation sequencing technology, it will definitely promote the in-depth study of gut bacteria and thus help understand the taxonomic and metabolomic associations between bacteria and cancer. This review summarizes the tumorigenesis mechanisms of bacteria.