Polystyrene Nanoplastics Drive Colorectal Tumors in Mice by Disrupting Gut Microbiome and Immunity

Polystyrene nanoplastics, among the most pervasive environmental contaminants, may actively promote colorectal cancer rather than merely passing through the gut, according to a study published in Molecular Cancer. Using a murine azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colorectal cancer model, researchers report that chronic oral exposure to polystyrene nanoplastics (PS-NPs) promoted colorectal tumorigenesis through disruption of the gut microbiota–metabolite–immune axis.

The mechanistic picture emerging from the study’s multi-omics and functional analyses is strikingly specific. PS-NPs accumulated predominantly in the colon and caused structural damage to intestinal epithelial microvilli, and this coincided with a shift in the gut microbial community: the beneficial bacterium Faecalibaculum rodentium became depleted in nanoplastic-exposed animals.

That microbial loss carried a metabolic consequence. F. rodentium is a source of propionic acid, a protective metabolite, and its depletion led to a measurable reduction in this compound. The metabolic perturbation then cascaded into the immune system, attenuating Th17 cell differentiation and IL-17A production. Rather than being a pro-inflammatory driver in this context, the Th17/IL-17A pathway here functioned as part of anti-tumor immunity, and its impairment left the intestinal environment less able to suppress tumor formation.

The researchers also extended their observations into the clinic, detecting diverse microplastics in colorectal cancer patient tissues and blood.

Collectively, the study delineates a mechanistic pathway linking environmental nanoplastic exposure to colorectal carcinogenesis via what the authors call the F. rodentium–propionic acid–Th17 cell axis. The findings highlight the gut microbiome and its metabolites as potential targets for intervention against pollution-associated cancer risks, while underscoring that the results derive from an animal model of chemically induced tumorigenesis and require further investigation to establish relevance to human disease.

Subject of Research: How polystyrene nanoplastics may promote colorectal cancer through gut microbiota, metabolite and Th17 immune cell disruption

Article Title: Polystyrene nanoplastics promote colorectal tumorigenesis via gut microbiota-metabolite-Th17 cell axis

Article References: Fei, J., Jiang, Z., Zhang, P., Peng, Y., Wang, K., Zhu, J., Li, Y., Tang, Y., Zou, X., Fu, S., Yan, W., Huang, S., Shen, H., Zeng, S., & Han, Y. (2026). Polystyrene nanoplastics promote colorectal tumorigenesis via gut microbiota-metabolite-Th17 cell axis. Molecular Cancer. https://doi.org/10.1186/s12943-026-02823-2

Image Credits: AI Generated

DOI: 10.1186/s12943-026-02823-2

Keywords: polystyrene nanoplastics, colorectal cancer, gut microbiota, Faecalibaculum rodentium, propionic acid, Th17 cells, IL-17A, microbiome dysbiosis, AOM/DSS model, microplastics, Polystyrene, nanoplastics