Micro‐ and nanoplastics in gastrointestinal disorders: Mapping the translational gap between exposure, biomonitoring, and pathogenic mechanisms

Abstract Micro‐ and nanoplastics (MNPs) have become pervasive environmental contaminants with increasing evidence linking them to adverse health outcomes. As ingestion constitutes a primary exposure route, the gastrointestinal tract represents a critical biological interface for MNPs‐host interactions and subsequent pathological manifestations. This review systematically synthesizes current knowledge regarding MNPs physicochemical properties, human exposure pathways, and their emerging role in gastrointestinal disorders. The inherent physicochemical heterogeneity of MNPs presents significant challenges for accurate detection and toxicological evaluation. Human populations are predominantly exposed through dietary intake, inhalation, and dermal contact. Standardized fecal detection protocols are critically needed for reliable quantification and cross‐study harmonization. Current evidence indicates MNPs disrupt gastrointestinal homeostasis through multiple mechanisms, including epithelial barrier impairment, immune‐mediated inflammation, oxidative stress‐induced cytotoxicity, and gut microbial dysbiosis. Importantly, this review highlights a critical “translational gap” linking environmental exposure assessment, human biomonitoring evidence, and mechanistic toxicology. By integrating these currently disconnected research domains, this framework aims to facilitate a more coherent understanding of how environmental MNPs exposure may contribute to the pathogenesis of gastrointestinal disorders.