Global research trends and mechanistic pathways linking micro- and nano plastics exposure to metabolic health: a bibliometric and evidence-mapping analysis (2013–2025)

Background The widespread presence of micro- and nanoplastics (MNPs) in the food chain has raised concerns regarding their potential contribution to metabolic diseases. Objective However, a comprehensive synthesis of the intellectual structure, thematic evolution, and biomarker evidence linking dietary MNP exposure to metabolic health outcomes remains limited. Methods This study conducted a bibliometric analysis of publications indexed in Scopus and Web of Science Core Collection (WoS) between 2013 and 2025. Bibliometrix/Biblioshiny and VOSviewer were applied for performance analysis, science mapping (co-occurrence, co-citation, bibliographic coupling), thematic evolution, and biomarker-domain mining. A biomarker–mechanism evidence matrix was developed to integrate mechanistic insights. Results 1,613 entries were found in WoS out of the 1,725 papers in the Scopus dataset, indicating consistent publication trends across databases. After 2019, there was a significant increase in annual research production, which was indicative of the expanding interdisciplinary attention to metabolic concerns linked with MNP. The publication landscape is dominated by environmental toxicology journals, which are increasingly contributing worldwide and have a large geographic concentration in China. Four important research areas were found by keyword co-occurrence analysis: mammalian metabolic toxicity, gut microbiota dysbiosis, aquatic ecotoxicology, and developing human health risk assessment. Oxidative stress and exposure pathways were identified as major themes by thematic mapping, while gut microbiota–metabolic interactions represent quickly developing research avenues. Conclusion Human epidemiological evidence remains limited compared to animal mechanistic studies, highlighting gaps in realistic exposure assessment and standardized cardiometabolic biomonitoring.