Microplastics and the gut-brain axis: Unraveling neurotoxic mechanisms and health implications
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PUBLIC SUMMARY
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Microplastics impair intestinal barrier integrity and disrupt gut microbial balance.
Microplastics induce gut dysbiosis that drives systemic inflammation and oxidative stress.
Microplastics trigger gut-brain axis signaling that propagates inflammatory stress to the brain.
Microplastics may contribute to neurodevelopmental and neurodegenerative disorders.
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ABSTRACT
Microplastics (MPs) are emerging environmental contaminants with increasing global prevalence, leading to inevitable human exposure through ingestion, inhalation, and dermal absorption. Despite the protective role of the blood-brain barrier (BBB), MPs can translocate and accumulate in the brain, raising concerns about their potential neurotoxicity. This review systematically evaluates the neurotoxic mechanisms of MPs, emphasizing their occurrence in the gastrointestinal tract and interaction with the gut-brain axis. MPs can disrupt intestinal barrier integrity, alter gut microbiota composition, and induce systemic inflammation, ultimately affecting neurotransmitter homeostasis. These disturbances may propagate to the central nervous system through neuroinflammatory pathways, oxidative stress, and dysregulated neurotransmission. Additionally, we discuss potential mechanisms of BBB penetration by MPs and their implications for neurodegenerative and neurodevelopmental disorders. It also highlights environmental exposure risks, technological challenges in assessing MPs’ toxicity in real-world conditions, and current research gaps. We emphasize the urgent need for human-based studies to elucidate the long-term health risks associated with MPs exposure, and implementing comprehensive strategies and policies to reduce reliance on conventional plastics and promote sustainable material alternatives can serve as an effective approach to mitigating MPs consumption. -
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Farooq U., Muhammad Z., Yang Q., et al. (2026). Microplastics and the gut-brain axis: Unraveling neurotoxic mechanisms and health implications. The Innovation Medicine 4:100190. https://doi.org/10.59717/j.xinn-med.2026.100190
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Farooq U., Muhammad Z., Yang Q., et al. (2026). Microplastics and the gut-brain axis: Unraveling neurotoxic mechanisms and health implications. The Innovation Medicine 4:100190. https://doi.org/10.59717/j.xinn-med.2026.100190
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Figure 1.
Suggested Adverse Outcome Pathway (AOP) for the oral ingestion of MPs within humans (Crown Copyright © 2023 Published by Elsevier B.V).18
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Figure 2.
Exposure pathways of MPs (© 2024 Elsevier B.V. All rights reserved).
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Figure 3.
An innate response in producing and regulating both pro- and anti-inflammatory cytokines from bone-marrow-derived macrophages induced by MPs.42
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Figure 4.
Risks of neurological diseases induced by MPs and possible mechanisms (This figure was created by BioRender.com).
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Figure 5.
Impact of MPs exposure on the GBA (© 2021 MDPI under CC BY 4.0).82
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Figure 6.
Schematic representation of the correlation between chronic intestinal inflammation and the development of brain disorders by MP exposure (This figure was created by BioRender.com).
