The role of oncobiosis, characterized by dysregulated microbial ecosystems associated with cancer, has been increasingly acknowledged in promoting the metastasis and dissemination of tumour cells. A comprehensive understanding of the complex interactions between the gut microbiome and metastatic colorectal cancer (mCRC) presents promising avenues for the development of innovative therapeutic approaches centred around modulating the gut microbiome to prevent or hinder metastatic spread. In this comprehensive review, we aim to provide a molecularly focused summary of the implications of the human gut microbiome and microbial metabolites in the initiation and advancement of mCRC. By elucidating these intricate mechanisms, we strive to establish a foundation for future research and the design of novel interventions targeting the gut microbiome to combat this devastating disease.
