The Plastic Burden: How Microplastic Exposure Shapes Gut Microbiota, Immune Function, and Reproductive Outcomes – A Review

Microplastic pollution has emerged as a ubiquitous environmental contaminant with profound implications for human health. These particles, defined as plastic fragments smaller than 5 mm, have been detected throughout the human body, including in blood, brain tissue, placenta, and reproductive organs. This comprehensive review examines the multifaceted impacts of microplastic exposure on three interconnected biological systems: gastrointestinal health and gut microbiota, immune function, and reproductive outcomes. Evidence demonstrates that microplastics disrupt gut microbiome composition, trigger chronic inflammatory responses, compromise intestinal barrier integrity, and interfere with endocrine pathways essential for reproductive health. Mechanistically, microplastics induce oxidative stress, activate pro-inflammatory cascades, and serve as vectors for endocrinedisrupting chemicals. Recent studies reveal concerning bioaccumulation patterns, with brain tissue showing 50% higher microplastic concentrations in 2024 compared to 2016 samples. The detection of microplastics in placental tissues and umbilical cord blood raises critical concerns about transgenerational health impacts. This review synthesizes current evidence on exposure pathways, biological mechanisms, and health consequences while identifying critical research gaps and potential therapeutic interventions.