Microplastic exposure and obesity-related metabolic dysfunction: A proposed gut microbiota-metabolite framework

Microplastics (MPs), as emerging global contaminants, have infiltrated aquatic systems, soil, and food chains, raising concerns about their health risks, particularly their potential link to metabolic disorders like obesity. This review evaluates evidence that MP exposure may influence host energy metabolism and adipogenesis and examines the potential involvement of the gut microbiota and its metabolites. Dietary MP exposure can alter microbial communities and associated metabolic pathways. Such dysbiosis may impair intestinal barrier integrity, trigger chronic inflammation, and promote adipose dysfunction, thereby potentially contributing to obesity-related metabolic disturbances. We synthesize findings from animal studies, in vitro models, and multi-omics approaches, highlighting the roles of MP physicochemical properties, exposure dose, and duration in obesity-related metabolic effects. Current limitations include insufficient long-term assessments at environmentally relevant concentrations, uncertainties in cross-species extrapolation, and unclear interactions with co-pollutants. Future studies could combine organ-on-a-chip (OoC) models with microbial and host single-cell or spatial approaches to test microbiota-host crosstalk. Overall, this review synthesizes emerging evidence on the potential links between MP exposure and adipogenesis dysregulation and identifies priorities for future mechanistic research and risk assessment.