Research progress in intratumoral microbiota: unlocking the potential of cancer immunotherapy

In recent years, intratumoral microbiota (ITM), a crucial component of the tumor microenvironment, have received increasing attention because of their role in cancer immunotherapy. ITM not only influence tumor initiation and progression but also modulate local and systemic immune responses, thereby affecting the efficacy of immune checkpoint inhibitors and other immunotherapeutic approaches. This review summarizes the compositional characteristics of ITM, their immunoregulatory mechanisms, and their effects on tumor metastasis and responsiveness to immunotherapy. Particular emphasis is placed on interactions between intratumoral microbiota and immune therapies across cancer types, highlighting potential therapeutic strategies that exploit these microbial influences. Furthermore, the review discusses current challenges in integrating intratumoral microbiota into immunotherapeutic paradigms and outlines future research directions. By providing a comprehensive overview of the role of ITM in cancer immunity, this review aims to support advances in precision oncology and foster novel approaches to enhance immunotherapy outcomes.