Live-pathogenic bacteria, which were identified inside tumors hundreds year ago, are key elements in modern cancer research. As they have a relatively accessible genome, they offer a multitude of metabolic engineering opportunities, useful in several clinical fields. Better understanding of the tumor microenvironment and its associated microbiome would help conceptualize new metabolically engineered species, triggering efficient therapeutic responses against cancer. Unfortunately, given the low microbial biomass nature of tumors, characterizing the tumor microbiome remains a challenge. Tumors have a high host versus bacterial DNA ratio, making it extremely complex to identify tumor-associated bacteria. Nevertheless, with the improvements in next-generation analytic tools, recent studies demonstrated the existence of intratumor bacteria inside defined tumors. It is now proven that each cancer subtype has a unique microbiome, characterized by bacterial communities with specific metabolic functions. This review provides a brief overview of the main approaches used to characterize the tumor microbiome, and of the recently proposed functions of intracellular bacteria identified in oncological entities. The therapeutic aspects of live-pathogenic microbes are also discussed, regarding the tumor microenvironment of each cancer type.

数百年前在肿瘤内发现的活病原菌是现代癌症研究的关键要素。由于它们具有相对容易获得的基因组，因此它们提供了大量的代谢工程机会，可用于多个临床领域。更好地了解肿瘤微环境及其相关微生物组将有助于概念化新的代谢工程物种，引发针对癌症的有效治疗反应。不幸的是，鉴于肿瘤的微生物量低，表征肿瘤微生物组仍然是一个挑战。肿瘤具有较高的宿主与细菌 DNA 比率，因此识别肿瘤相关细菌极为复杂。然而，随着下一代分析工具的改进，最近的研究表明，在确定的肿瘤内存在肿瘤内细菌。现在已经证明，每种癌症亚型都有一个独特的微生物组，其特征是具有特定代谢功能的细菌群落。本综述简要概述了用于表征肿瘤微生物组的主要方法，以及最近提出的在肿瘤实体中鉴定的细胞内细菌的功能。关于每种癌症类型的肿瘤微环境，还讨论了活病原微生物的治疗方面。以及最近提出的在肿瘤实体中鉴定的细胞内细菌的功能。关于每种癌症类型的肿瘤微环境，还讨论了活病原微生物的治疗方面。以及最近提出的在肿瘤实体中鉴定的细胞内细菌的功能。关于每种癌症类型的肿瘤微环境，还讨论了活病原微生物的治疗方面。