Microplastics in poultry: Sources, bioaccumulation and human health consequences

The widespread use and environmental persistence of plastics have led to growing concerns about microplastic (MP) contamination across food systems including poultry production. This review summarizes current knowledge on the sources, pathways of transmission and impacts of MPs in poultry, highlighting their potential risks to animal and human health. Poultry are highly exposed to MPs through contaminated feed ingredients, drinking water, litter and the surrounding environment. Plastic residues from feed packaging, degraded farm equipment and atmospheric deposition contribute further to contamination. Once ingested, MPs can accumulate in the gastrointestinal tract, liver, kidneys, spleen, and muscle tissues of birds, disrupting metabolic, immune and reproductive functions. Reported effects include gut dysbiosis, oxidative stress, liver dysfunction, mitochondrial damage and altered gene expression related to muscle and reproductive physiology. These changes may impair growth, meat quality and egg production. Moreover, MP contaminated poultry products can serve as a potential route of MP transmission to humans, posing additional health risks such as inflammation and oxidative stress. Despite increasing evidence of their biological impacts, research on MP exposure in poultry remains limited and the assessment of human risk continues to be qualitative because of the insufficient exposure data available for edible products. Addressing this emerging issue requires improved detection methods, stronger regulatory frameworks and increased awareness among producers and consumers. While MPs have been extensively researched in aquatic species, studies focused on poultry are very limited and are in the early stages of development. A multidisciplinary approach integrating veterinary, environmental, and public health perspectives is essential to mitigate MP contamination and ensure sustainable, safe poultry production.