The intratumoral microbiota: from origin and identification to function and therapeutic perspective

Tumor tissues, once considered sterile, actually host diverse microbial communities that play key roles in several physiological and pathological processes, closely related to tumorigenesis and progression. Studies have demonstrated that intratumoral microbiota potentially contributes to immune regulation and significantly influences cancer treatment outcomes. Here, we aim to provide an extensive review of the conceptual framework, potential origins, spatial heterogeneity, and analytical methodologies of intratumoral microbiota, explore their carcinogenic mechanisms and potential role in tumor prognosis. In addition, we discuss current therapeutic strategies that target intratumoral microbiota and highlight the research prospects and limitations in this field, although there are some inevitable challenges.