Some species of microbe found in the human gut can absorb PFAS - the potentially toxic and long-lasting so-called ‘forever chemicals,’ according to a new study.
The researchers say boosting these species in our gut microbiome could help protect against the harmful effects of PFAS.
Per- and polyfluoroalkyl substances – PFAS - are a group of more the 4,700 chemicals that have been used since about the 1940s in all sorts of products from cookware to clothes and carpets. While PFAS can have very different chemical make-ups, what PFAS molecules share is a chain of strongly-linked carbon and fluorine atoms. It’s these strong bonds which mean they can take decades or longer to degrade. While some PFAS get cleared out of the human body in urine in a matter of days, others with a longer molecular structure can hang around in the body for years.
PFAS have been linked with a range of health issues including decreased fertility, developmental delays in children, and a higher risk of certain cancers and cardiovascular diseases as well as impacts on the immune system.
Now scientists at the University of Cambridge have identified a family of bacterial species found naturally in the human gut, that are able to absorb various PFAS molecules from their surroundings.
The results are published in the journal Nature Microbiology.
Nine of these bacterial species were introduced into the guts of mice to ‘humanise’ the mouse microbiome, and the bacteria accumulated the PFAS eaten by the mice - which were then excreted in faeces.
The researchers said their results are the first evidence that our gut microbiome could play a helpful role in removing toxic PFAS chemicals from our body, however this has not yet been directly tested in humans.
Kiran Patil, in the University of Cambridge’s MRC Toxicology Unit and senior author of the report, said: “We found that certain species of human gut bacteria have a remarkably high capacity to soak up PFAS from their environment at a range of concentrations, and store these in clumps inside their cells. Due to aggregation of PFAS in these clumps, the bacteria themselves seem protected from the toxic effects.”
The researchers plan to create probiotic dietary supplements that boost the levels of these helpful microbes in the gut to protect against the toxic effects of PFAS.
Anna Lindell, a researcher at the University of Cambridge’s MRC Toxicology Unit and first author of the study said: “We’re all being exposed to PFAS through our water and food – these chemicals are so widespread that they’re in all of us. “PFAS were once considered safe, but it’s now clear that they’re not. It’s taken a long time for PFAS to become noticed because at low levels they’re not acutely toxic.”
Lindell and Patil have co-founded a startup, Cambiotics, with entrepreneur Peter Holme Jensen to develop probiotics that remove PFAS from the body.
In the UK, the House of Commons Environmental Audit Committee launched an investigation earlier this year which aims to understand the risks of PFAS in the UK and whether research institutions and agencies are equipped to monitor their impact.
More on PFAS
- PFAS: Researchers investigate destruction of forever chemicals by incineration
- Micropollutants: The challenge of removing them from wastewater [Premium]
- Farewell, forever chemicals
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