Nanomaterial-mediated modulation of gut microbiota for precision diagnosis and treatment of colorectal cancer: a comprehensive review

The critical role of gut microbiota in the initiation and progression of colorectal cancer (CRC) has garnered widespread recognition. Leveraging their precise targeting capabilities and programmable properties, nanomaterials are emerging as novel strategy for modulating the interplay between microbiota and tumors. This comprehensive review examines functional nanomaterials-including nanoparticles, nanocapsules, and nanoreactors-and elucidates their mechanisms of action in remodeling the CRC immune microenvironment and potentiating responses to chemoradiotherapy and immunotherapy through microbiota modulation. We further highlight the synergistic value of nanomaterials in multimodal CRC theranostics: (i) serving as microbiota modulation carriers for integrated diagnosis and therapy; (ii) activating systemic anti-tumor immunity via the gut-microbiota-immune axis; and (iii) targeting CRC drug resistance and metastasis. Finally, we discuss challenges associated with clinical translation, including assessment of long-term nanomaterial biosafety and optimization of personalized microbiota intervention protocols. This review provides theoretical foundations and technical insights for developing precision diagnostic and therapeutic strategies for CRC based on nano-microbiota interactions.