The growing presence of microplastics in our food and water supply has raised serious concerns about their effects on human health. These tiny plastic particles can carry harmful chemicals, making them more than just harmless debris. In a newly published study, researchers aimed to understand how polystyrene microplastics and Benzo[a]pyrene—a toxic chemical found in the environment—affect kidney health when they interact inside the digestive system.
Dr. Hailong Zhouand his team from Hainan University and Shanxi Medical University showed that this harmful combination can lead to a special kind of cell damage in the kidneys. This type of cell death is known as ferroptosis, which is a process where cells die due to an overload of certain fats and iron that become toxic. Ferroptosis is different from other types of cell death like apoptosis or necrosis because it is driven specifically by iron and fat damage. Their findings were published in the journal Communications Biology.
Dr. Zhouand’s team found that when both polystyrene microplastics and Benzo[a]pyrene were consumed together, the damage to kidney tissues was much worse than when either one was consumed alone. Together, they disrupted how the kidneys handle fats and iron, causing more fats to break down and more iron to gather inside cells. This triggered a chain reaction that led to oxidative stress, which is a harmful condition where unstable molecules known as free radicals build up and damage cells. Free radicals are molecules that can react with and damage important parts of cells, such as DNA and cell membranes. The result was ferroptosis, which harmed the kidneys’ ability to function properly.
A key discovery was the role of the gut in this damaging process. The combined exposure to microplastics and Benzo[a]pyrene harmed the lining of the intestine, weakened the proteins that normally keep intestinal cells tightly sealed, and disturbed the balance of helpful and harmful bacteria in the digestive system. This led to what is commonly called a “leaky gut,” a condition where the intestinal wall becomes more porous and allows substances to pass through that normally wouldn’t. Harmful compounds like arachidonic acid—a type of fat involved in inflammation, which can worsen tissue damage—could escape from the intestines into the bloodstream. Once in the blood, these substances traveled to the kidneys, where they caused further damage. As Dr. Zhouand explained, “The severe damage to the intestinal barrier results in thinning of the intestinal wall, leading to an increase in intestinal metabolites, which are small molecules created during digestion, and these pass to the kidneys through what scientists call the gut-kidney axis.” The gut-kidney axis is the communication link between the gut and kidneys, where problems in the gut can influence kidney function.
Once these substances reached the kidneys, they activated certain biological processes. Two key proteins—long-chain fatty acid Coenzyme A ligase 4 and lysophosphatidylcholine acyltransferase 3—were found to be more active. These proteins help the body break down and store fats, playing a role in managing energy and maintaining cell membrane structure. When they became too active, it led to an unhealthy buildup of fat-related byproducts that triggered cell death. “We found that protein expression of long-chain fatty acid Coenzyme A ligase 4 and lysophosphatidylcholine acyltransferase 3 was significantly upregulated, meaning the body was producing more of them than usual… indicating that the uptake of polystyrene microplastics and Benzo[a]pyrene does indeed lead to renal ferroptosis,” explained Dr. Zhouand. Renal refers to the kidneys.
What makes these findings especially concerning is that the amount of microplastics and Benzo[a]pyrene used in the study was similar to what people might be exposed to over time by drinking water and eating food contaminated with plastics and pollutants. This means the risks identified in the study could realistically apply to everyday life, making it urgent to understand and reduce microplastic contamination.
In the end, the study draws attention to a newly recognized risk: that damage to the digestive system caused by microplastics and pollutants can indirectly harm the kidneys. This chain of events, known as the gut-kidney axis, refers to the close connection between gut health and kidney health, showing how problems in one organ can lead to issues in another. As Dr. Zhouand noted, “This study highlights the combined toxicity of polystyrene microplastics and Benzo[a]pyrene in mammals and uncovers the specific pathways and mechanisms by which exogenous pollutants, meaning substances that come from outside the body, harm the gut-kidney axis in animals.”
Journal Reference
Zhang Y., Men J., Yin K., Zhang Y., Yang J., Li X., Wang X., Diao X., Zhou H. “Activation of gut metabolite ACSL4/LPCAT3 by microplastics in drinking water mediates ferroptosis via gut–kidney axis.” Communications Biology, 2025. DOI: https://doi.org/10.1038/s42003-025-07641-8
About the Author
Dr. Hailong Zhou is a prominent biomedical scientist based at Hainan University, where he serves as a leading figure in health and environmental research. With a research focus that spans toxicology, cellular biology, and environmental pollutants, Dr. Zhou has made significant contributions to understanding how external contaminants such as microplastics and chemical pollutants affect internal organs, particularly the kidneys and gastrointestinal system. He is known for his work investigating the gut–kidney axis, a complex biological pathway that links digestive health to kidney function. Dr. Zhou’s interdisciplinary approach blends molecular science with public health relevance, aiming to uncover the mechanisms behind pollutant-induced diseases. He has led and collaborated on numerous peer-reviewed studies and is respected for his ability to translate laboratory insights into real-world health implications. Through his research leadership and academic mentorship, Dr. Zhou continues to influence the growing field of environmental health science.
