Gut microbes could protect us from toxic ‘forever chemicals’

Scientists have discovered that certain species of microbe found in the human gut can absorb PFAS - the toxic and long-lasting ‘forever chemicals.’ They say boosting these species in our gut microbiome could help protect us from the harmful effects of PFAS.

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.

Scientists at the University of Cambridge have identified a family of bacterial species, found naturally in the human gut, that absorb various PFAS molecules from their surroundings.  When nine of these bacterial species were introduced into the guts of mice to ‘humanise’ the mouse microbiome, the bacteria rapidly accumulated PFAS eaten by the mice - which were then excreted in faeces.

The researchers also found that as the mice were exposed to increasing levels of PFAS, the microbes worked harder, consistently removing the same percentage of the toxic chemicals. Within minutes of exposure, the bacterial species tested soaked up between 25% and 74% of the PFAS.

The results are the first evidence that our gut microbiome could play a helpful role in removing toxic PFAS chemicals from our body - although this has not yet been directly tested in humans.

The researchers plan to use their discovery to create probiotic dietary supplements that boost the levels of these helpful microbes in our gut, to protect against the toxic effects of PFAS.

The results are published today in the journal Nature Microbiology.

PFAS (Perfluoroalkyl and Polyfluoroalkyl Substances) can’t be avoided in our modern world. These man-made chemicals are in many everyday items including waterproof clothing, non-stick pans, lipsticks and food packaging, used for their resistance to heat, water, oil and grease. But because they take thousands of years to break down, they are accumulating in large quantities in the environment – and in our bodies.

Dr Kiran Patil, in the University of Cambridge’s MRC Toxicology Unit and senior author of the report, said: “Given the scale of the problem of PFAS ‘forever chemicals’, particularly their effects on human health, it’s concerning that so little is being done about removing these from our bodies.”

“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.”

Dr Indra Roux, a researcher at the University of Cambridge’s MRC Toxicology Unit and a co-author of the study said: “The reality is that PFAS are already in the environment and in our bodies, and we need to try and mitigate their impact on our health now. We haven’t found a way to destroy PFAS, but our findings open the possibility of developing ways to get them out of our bodies where they do the most harm.”

There is increasing concern about the environmental and health impacts of PFAS, and in April 2025 the UK launched a parliamentary inquiry into their risks and regulation.

There are over 4,700 PFAS chemicals in widespread use. Some get cleared out of the body in our urine in a matter of days, but others with a longer molecular structure can hang around in the body for years.

Dr 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. But they’re like a slow poison.”

Lindell and Patil have co-founded a startup, Cambiotics, with serial entrepreneur Peter Holme Jensen to develop probiotics that remove PFAS from the body, and they are investigating various ways of turbo-charging the microbes’ performance. Cambiotics is supported by Cambridge Enterprise, the innovation arm of the University of Cambridge, which helps researchers translate their work into globally-leading economic and social impact.

While we wait for new probiotics to become available, the researchers say the best things we can do to help protect ourselves against PFAS are to avoid PFAS-coated cooking pans, and use a good water filter.