22. February 2019
Nanoparticles from Food Mask Gut Bacteria

Nanoparticles in food can cover bacteria like a sort of mask. This is what Shirley Knauer from the University of Duisburg-Essen and her team discovered. They observed the nanoparticles within the different environments of the gastrointestinal tract simulated in the laboratory.

Nanoparticles are found in many foods. They are either intentionally added or already present in the food (such as in beer). But what happens exactly to the smallest particles in the gut? Knauer’s team simulated the different environments of the gastrointestinal tract in the laboratory. They discovered that many nanosized substances dock onto the bacteria.

“Our results give rise to strategies for further developing nanoparticles in food. There is enormous potential not just for the application but also for foundational research, including food allergies”, says the Knauer, a molecular biologist, who led the study.

The stomach has an acidic environment, which is why gastric juice is also called stomach acid. The pH in the rest of the digestive tract is fairly neutral. This has a number of effects, says Knauer: “The body’s own immune defence doesn’t recognise bacteria covered with nanoparticles as efficiently, which can lead to increased inflammation.” But nanoparticles also have positive effects. Silica (silicon dioxide) nanoparticles inhibited the infectivity of the bacteria Helicobacter pylori, the main agent involved in gastric ulcers and gastric cancer.

The research group is continuing its work on understanding the potential negative or positive effects of nanoparticles consumed with food. The results have been published in the journal npj Science of Food.


Du bist, was du isst: Nanopartikel beeinflussen Darm-Mikrobiom. Universität Duisburg-Essen, 23.01.2019

Siemer S et al. Nanosized food additives impact beneficial and pathogenic bacteria in the human gut: a simulated gastrointestinal study. npj Science of Food. 2018;2:22


Text: kf/ktg