HMN 2025: How Artificial digestion models may misjudge nanoplastic risks in the human gut

The prevalence of microplastics and nanoplastics in the human body is an increasing concern. Studies revealed that human brain tissues contain seven to 30 times more particles than other organs, such as the liver and kidneys. Individuals are estimated to consume between 39,000 and 52,000 microplastic particles annually through food and water. These findings underscore the urgent need to accurately assess the potential health impacts of nanoplastics.

Researchers from Taiwan have revealed that current artificial digestion methods may significantly underestimate the size and thereby overestimate potential risks of nanoplastics in the human gastrointestinal tract. This discovery, published in the Journal of Hazardous Materials, underscores the need for more accurate assessment models to better evaluate human exposure to these pervasive plastic particles.

This study is critical because it shows how nanoplastics—tiny plastic particles often found in food packaging and consumer products—behave within the human digestive system. Since ingestion is a primary route of exposure to these potentially harmful materials, understanding how they act inside the body is critical for ensuring food safety and protecting public health.

In the study, researchers simulated digestion using artificial fluids and compared these findings to human and animal digestive fluids. They used fluorescent labeling and advanced particle tracking technology to measure particle sizes, precisely avoiding interference from digestive substances.

The team discovered that polystyrene and melamine-formaldehyde nanoplastics form aggregates during digestion, a process influenced by acidity, salts, and proteins. Moreover, when comparing artificial digestion to actual digestive fluids, the artificial models consistently produced smaller aggregates, suggesting that these models may underestimate the actual size of nanoplastics.

The study also revealed that although food did not significantly change the particle size, it notably altered the protein composition around the nanoplastics, which can affect their biological interactions. These findings underscore the limitations of current artificial digestion models and highlight the importance of using actual digestive conditions.

“Our research indicates that to truly understand the risks posed by nanoplastics, we must develop more accurate models that reflect real human digestive conditions,” said Prof. I-Lun Hsiao, the lead researcher from Taipei Medical University.

This study emphasizes the need to refine our assessment models to better understand and mitigate the potential health risks associated with nanoplastic ingestion. As plastic pollution continues escalating, ensuring accurate evaluations of human exposure is essential for public health and safety.

Provided by
Taipei Medical University

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