Scientists believe the plastic was ingested through plastic-wrapped food or drinking from plastic bottles. "Now that we have first evidence for microplastics inside humans, we need further research to understand what this means for human health", Schwabl said.
Microplastics are tiny pieces of plastic smaller than 5 millimeters, either found in products like exfoliants or disintegrated from larger pieces of plastic such as those that often end up in the ocean.
The research from the Medical University of Vienna and the Environment Agency Austria analysed and tracked stool samples from Europe and Asia, including Finland, Italy, Japan, the Netherlands, Poland, Russia, the United Kingdom and Austria.
Scientists collected samples from eight participants in the UK, Finland, Italy, the Netherlands, Poland, Russia and Austria - and found that every single sample contained tiny particles of up to nine types of plastic.More news: Meghan Markle wears same dress as Prince Harry's ex-girlfriend
Still, data on human exposure to microplastics is scarce, and the new study is the first to quantify the particles in human stool, the researchers said.
A group of Austrian researchers have found evidence that microplastics - extremely small pieces of plastic beads, fibres, or fragments - accumulate in human faeces.
Of those who participated in the study, none were vegetarians, and six ate fish. The most common forms were polypropylene-commonly used in bottle caps and in packaging for food like yogurt-and PET, commonly used in water bottles.
"Of particular concern is what this means to us, and especially patients with gastrointestinal diseases", said Philipp Schwabl, the study's lead and a researcher at the Medical University of Vienna.More news: Meghan joins Prince Harry to meet royal fans after rest
On average, there were 20 microplastic particles in every 10 grams of poop.
"We will also be exposed to particles from house dust, food packaging materials and the use of plastic bottles". Indeed, microplastics have been detected in seafood, including tuna, lobster and shrimp, the researchers said.
Dr Stephanie Wright, a King's College London research fellow, said more work was needed to show whether it built up inside the body or just passed through.Alistair Boxall, environmental science professor at the University of York, said: 'It is really hard to conclude whether there is a risk to health or not'.More news: Masked robbers attempt to break into Victoria and David Beckham's Cotswolds home
The research did not determine where each of the plastic particles came from. "It is therefore inevitable that at least some of these things will get into our lungs and digestive system".