Plastic particles increase inflammation and cross barriers

Lukas Kenner, visiting professor, Department of Molecular Biology. 

ImageMedizinische Universität Wien

"Our results show that microplastics and nanoplastics are an underestimated factor both in how chronic inflammatory bowel diseases develop and that they can also affect other body organs," says Lukas Kenner, visiting professor at Umeå University, professor at the Medical University of Vienna and research leader for the study.

underestimated factor

The researchers have investigated a possible connection between the increasing number of people with chronic inflammatory bowel disease and the increased exposure to micro- and nanoplastics, MNPs.

Common disease

The harmful effects of MNP were investigated in mice with ulcerative colitis, one of the most common forms of chronic inflammatory bowel disease. The study focused on polystyrene particles of different sizes that the mice were fed. Polystyrene is a very common plastic used for food packaging such as yoghurt cups or takeaway boxes.

Molecular and histological analyses in the study showed interactions between MNP and intestinal inflammation. The uptake of MNP in the intestinal mucosa increased during inflammatory conditions. Exposure to MNP also intensified the inflammatory immune response in the gut by triggering a pro-inflammatory activation of certain immune cells, macrophages. In addition, exposure to MNP led to disruption of the gut microbiome; beneficial bacterial species decreased, while pro-inflammatory and potentially harmful bacterial species increased.

Beyond the gut

The study shows effects even beyond the intestines. It was possible to see how micro- and nanoplastics also accumulated in other vital organs of the mice. It was mainly the very small nanoplastic particles, smaller than 0.0003 millimetres, that could be seen in the liver, kidneys and blood of the people. These results suggest that the smallest particles can cross the body's biological barriers and thus have effects far beyond the stomach and intestines.

The research has been carried out by researchers at the Universität Wien, CBMed GmbH in Graz, Medizinische Universität Wien and Umeå universitrt. The study is published in the scientific journal Microplastics and Nanoplastics.