Microplastics unwrapped Could particles be reshaping our bodies?

Plastics are found in our blood, brains and guts- and while the long-term effects are still unclear, there are simple ways to reduce exposure

- By Linda Geddes

Microplastics have been found almost everywhere: in blood, placentas, lungs - even the human brain. One study estimated our cerebral organs alone may contain 5g of the stuff, or roughly a teaspoon.

Now, researchers suspect these particles may meddle with our gut microbes. When Dr Christian Pacher-Deutsch at the University of Graz in Austria exposed gut bacteria from five healthy volunteers to five common microplastics, the bacterial populations shifted - along with the chemicals they produced. Some of these changes mirrored patterns linked to depression and colorectal cancer.

"While it's too early to make definitive health claims, the microbiome plays a central role in many aspects of wellbeing, from digestion to mental health," said Pacher-Deutsch, who presented his work at the recent United European Gastroenterology conference in Berlin. "Reducing microplastic exposure where possible is therefore a wise and important precaution."

So how much plastic do we each carry, does it really matter and can we do anything about it? Microplastics are shed from items such as packaging, clothes, paints, cosmetics and tyres. Some are tiny enough to slip through the linings of our lungs and guts into our blood and internal organs - even into our cells. What happens next is still largely unknown.

"Designing a definitive experiment is hard, because we're constantly being exposed to these particles," said Dr Jaime Ross, a neuroscientist at the University of Rhode Island in the US. "But we know microplastics are in almost every tissue that has been looked at, and recent studies suggest we're accumulating far more plastic now than 20 years ago."