Abstract
Intratumoral microbiota, which affects the physiological and pathological processes of the host, has attracted increasing attention from researchers. Microbials have been found in normal as well as tumor tissues that were originally thought to be sterile. Intratumoral microbiota is considered to play a significant role in the development of tumors and the reduction of clinical benefits. In addition, intratumoral microbiota are heterogeneous, which have different distribution in various types of tumors, and can influence tumor development through different mechanisms, including genome mutations, inflammatory responses, activated cancer pathways, and immunosuppressive microenvironments. Therefore, eliminating the intratumoral microbiota is considered one of the most promising ways to slow down the tumor progression and improve therapeutic outcomes. In this review, we systematically categorized the intratumoral microbiota and elucidated its role in the pathogenesis and therapeutic response of cancer. We have also described the novel strategies to mitigate the impact of tumor progression. We hope this review will provide new insights for the anti-tumor treatment, particularly for the elderly population, where such insights could significantly enhance treatment outcomes.