The objective of this study is to identify and characterize microplastics present in peritumoral and intratumoral tissues of colorectal cancer patients, and to investigate their associations with gut microbiome composition and metabolic profiles. By integrating microplastic analysis with metagenomic and metabolomic data, we aim to explore the potential impact of environmental microplastic exposure on tumor microenvironment alterations, microbial dysbiosis, and metabolic reprogramming in colorectal cancer.