Microplastics and Nanoplastics in the Human Intestine: A Review of Health Implications and Possible Dietary Interventions

Micro- and nanoplastics (MNPs) have emerged as pervasive dietary contaminants, yet their implications for human health remain poorly defined. This review synthesizes current evidence on MNP interactions with the gastrointestinal system, emphasizing barrier disruption, biotransformation, particle uptake, and gut microbiota dysbiosis. Experimental data indicate that particle size, polymer type, and surface properties critically influence intestinal uptake and toxicity, with smaller particles showing greater systemic translocation. Although human evidence is limited and methodologies lack standardization, preliminary associations link MNP exposure with inflammatory bowel disease and metabolic disturbances. Beyond risks, we highlight the role of dietary patterns in modulating exposure and effects: minimizing processed, packaged foods and enhancing fiber, antioxidants, and probiotics may reduce intestinal burden and mitigate oxidative and inflammatory responses. Bridging mechanistic insights with dietary strategies, this review underscores the urgent need for standardized detection methods, human cohort studies, and sustainable food system interventions. This review uniquely integrates mechanistic toxicology of dietary micro- and nanoplastics with actionable nutritional strategies, providing the first concise synthesis that links intestinal biology and particle toxicodynamics to specific dietary interventions (e.g., fiber, antioxidants, probiotics) and food-system measures aimed at reducing exposure and harm.