Huang_2025_Ecotoxicol.Environ.Saf_302_118748

Microplastics (MPs) entering the gastrointestinal tract of hosts through various pathways alter the community structure and metabolic activity of the gut microbiota, thereby affecting the normal physiological functions of the host. However, there is still huge knowledge gap in the effects of MPs on gut microbiota of organisms. This review mainly summarized comprehensively the response mechanism of gut microbiota of three typical organisms, including aquatic animal (fish), rodent (mouse), and soil animal (earthworm) after MPs entering their gastrointestinal tract. MPs pose substantial health risks to organisms, supported by increasing evidence from animal and human studies. MPs can impair the digestive systems of fish, mice, and earthworms, leading to reduce appetite, slow growth, and diminish reproductive capacity. Additionally, MPs can damage the intestinal mucosal barrier, further compromising health. MPs can increase the absorption of fat, and the lipase on the surface of lipid coated MPs can digest triglyceride, which maybe a potential mechanism leading to changes in fat metabolism. Meanwhile, this review also briefly elaborated a key step and important model for evaluating MPs using gut microbiota as the target organ. Ultimately, this review summarized the limitations in gut microbiota studies of MPs and their future development directions to better comprehend the effects of MPs on the animals and human gut microbiota.