Microplastics: An emerging environmental risk factor for gut microbiota dysbiosis and cancer development?

Microplastics (MPs) are contaminants of emerging concern, as increased exposure levels pose a major threat to animals and human health. These contaminants insidiously infiltrate the environment by dispersing in air, water, and soil, potentially entering the human food chain. Bioaccumulation of these unmetabolizable MPs in organisms of increasing trophic levels has heightened the urgency to develop approaches to mitigate their input in the environment and day-to-day life. In addition, a disquieting research conclusion suggests a cancer risk associated with these ubiquitous particles, shaking the foundation of our understanding of MPs pollution’s health risks. This review article discusses the current state of knowledge surrounding MPs. The major MPs sources, and how they, along with associated additive chemicals and pathogenic bacteria, find their way into the human body through the food chain are described. In addition, MPs’ potential to cause inflammation and their effects on the gut microbiome and immune system, which can lead to the development of various types of cancers, including lungs, liver, skin, bone marrow, breast, colon, ovarian, cervical, and prostate, and pancreas, metastasis, and development of chemotherapy resistance, are reviewed based on recent literature. Overall, this review has presented evidence of the complex interplay between MPs, gut health, and cancer which warrants in-depth investigation and exploration of effective preventive and lenitive strategies to safeguard vulnerable populations from the potential long-term effects of MPs exposure. • Microplastics (MPs) are ubiquitous in every facet of our lives. • Bioaccumulation of MPs in the food chain is increasing alarmingly. • MPs contaminate human blood, lungs, placenta, and other organs. • MPs cause an imbalance in gut microbiota, and inflammation, and affect the immune system. • MP and Nano-plastics (NPs) may contribute to an increased risk of carcinogenesis.