Mapping the biological effects of micro- and nanoplastics in mammalian intestinal models: a scoping review

Micro- and nanoplastics (MNPLs) are increasingly recognized as emerging environmental contaminants with potential implications for gastrointestinal health. Although experimental research on intestinal MNPL toxicity has expanded rapidly, the available evidence remains highly heterogeneous with respect to experimental models, polymer composition, particle size, particle condition, exposure scenarios, and biological endpoints. Therefore, a structured evidence map is needed to clarify dominant methodological patterns and identify key knowledge gaps in the field.

This study was conducted as a scoping review in accordance with the Joanna Briggs Institute framework and the PRISMA-ScR guidelines. A comprehensive search was performed in PubMed, Scopus, and Web of Science to identify eligible original in vitro, ex vivo, and in vivo experimental research investigating the biological effects of MNPLs in mammalian intestinal models. Data were extracted and synthesized based on experimental models, particle characteristics, exposure scenarios, and toxicological outcomes.