Bidirectional regulation of the gut microbiome-immune axis in the immune microenvironment of colorectal cancer and targeted interventions

The initiation and progression of colorectal cancer (CRC) are profoundly influenced by the complex interplay between the gut microbiota and the immune system, underscoring the clinical importance of exploring the bidirectional regulatory mechanisms of the microbiota-immune axis within the CRC immune microenvironment. Emerging evidence indicates that the composition and functional capacity of the gut microbiota play a vital role in modulating the host's immune responses, while the immune system, in turn, can reciprocally regulate the structure and function of the microbiota. Despite significant insights into the role of the microbiota-immune axis in CRC progression, several critical questions remain unanswered-including how microbial heterogeneity affects therapeutic outcomes and the specific consequences of dysregulated regulatory mechanisms on the immune microenvironment. This review aims to provide a comprehensive analysis of the compositional features of the CRC immune microenvironment, examine the bidirectional molecular mechanisms underpinning the microbiota-immune axis, and evaluate the potential of targeted therapeutic strategies, thereby offering novel research perspectives and clinical applications for CRC treatment.