Beyond Mammalian Models: Honeybees as Sentinels for Microplastic-Driven Gut Dysbiosis and Reproductive Dysfunction

Microplastics have become one of the most pervasive pollutants of the Anthropocene, yet the mechanistic frameworks used to explain their biological effects have been built almost entirely on mammalian and aquatic vertebrate models. This narrative review argues that the honeybee, Apis mellifera, and other managed and wild pollinators represent an underused but uniquely powerful sentinel system for microplastic research. We synthesise evidence across four connected themes: the routes by which pollinators encounter environmental microplastics; microplastic-induced gut dysbiosis and intestinal barrier dysfunction; the striking mechanistic convergence between microplastic exposure and pesticide-driven disruption of the bee gut microbiota; and the downstream reproductive and endocrine consequences that plausibly propagate along a gut-gonad axis. The honeybee offers a rare combination of features that no rodent or fish model can match: a simple, host-specific and experimentally tractable core gut microbiota; realistic, continuous exposure to airborne and floral microplastics through active foraging; and a reproductive biology that is central to both colony fitness and global food security. We show that although the mammalian literature has established clear pathways linking microplastics to dysbiosis, barrier failure, oxidative stress and reproductive impairment, the pollinator literature has documented exposure and gut disturbance in isolation, leaving the gut-to-gonad link almost entirely unexamined. We close by proposing a concrete, testable research agenda that positions pollinators as integrative sentinels for the microbiome-reproduction interface. Bringing these fields together is not merely additive; it reframes microplastic toxicology around an ecologically indispensable, environmentally realistic model.