Micro/nanoplastic-mediated gut dysbiosis and its impact on cardiac and neuroimmune function in zebrafish model: A...

The pervasive distribution of micro- and nanoplastics (M/NPs) across ecosystems necessitates a mechanistic investigation into their toxicological consequences. Chronic exposure to M/NPs through combined intestinal uptake and branchial contact in aquatic animals disrupts epithelial barrier integrity, alters gastric secretions and luminal pH, and induces microbial dysbiosis, evidenced by the depletion of commensal taxa and expansion of pathogenic strains. These local perturbations trigger systemic sequelae, including neurotoxicity and cardiotoxicity. Consequences on cross-species analyses demonstrate translational concordance, as human studies similarly link M/NP bioaccumulation with inflammatory bowel disease, cognitive decline, and cardiovascular dysfunction. Integrative multi-omics approaches, encompassing transcriptomic, metabolomic, and microbiome analyses, have begun to elucidate the molecular cascades underpinning M/NP toxicity, providing high-resolution insights into host-microbe-environment interactions. Notwithstanding these advances, critical gaps remain in chronic exposure modelling, capturing particle heterogeneity, and ensuring ecological realism. In this context, zebrafish (Danio rerio) provide a uniquely tractable system for gnotobiotic rearing, microbial transplantation, and live imaging, thereby enabling causal inference and functional validation in real-time. Collectively, this review establishes zebrafish as a pivotal model for elucidating M/NP-induced gut dysbiosis, neurotoxicity, and cardiotoxicity. Multi-omics analyses and translational evidence reveal systemic inflammation, immune-metabolic disruptions, and mechanistic links to human health, providing a foundation for targeted research, regulatory frameworks, and interventions to mitigate environmental M/NP exposure.