The "oral-gut axis" transmission of microorganisms in colorectal cancer: Insights from <i>Peptostreptococcus'</i> perspective

Colorectal cancer (CRC) is linked to gut microecological imbalances, and increasing evidence suggests that oral-gut microecosystem aberrant interactions also significantly contribute to CRC pathogenesis. The emerging "oral-gut axis" offers novel perspectives into the cross-organ microbial regulation. Notably, the oral bacterium <i>Peptostreptococcus</i> exhibits spatiotemporal specificity during CRC progression and may modulate gut microecology and CRC via this axis. This review examines the oral-gut microecological interplay and teases apart the multidimensional associations between <i>Peptostreptococcus</i> (e.g. <i>Peptostreptococcus stomatis</i>, <i>Peptostreptococcus anaerobius</i>) and CRC, including their heterogeneity across CRC patient groups and their dynamic evolution and spatial distribution during the "adenoma-carcinoma" sequence. It summarizes mechanisms whereby <i>Peptostreptococcus</i> influences CRC by promoting tumor cell proliferation, inducing epithelial-mesenchymal transition, and reshaping the tumor microenvironment. It also categorizes the key technologies in this field. Furthermore, this review highlights <i>Peptostreptococcus's</i> potential as a CRC biomarker and therapeutic target, proposing future intervention strategies targeting oral-derived microbes to stimulate further research.