Cambridge scientists find gut bacteria can remove toxic PFAS from the body

Cambridge scientists discover that certain gut bacteria can absorb and eliminate PFAS, toxic ‘forever chemicals’ linked to health risks

New research from the University of Cambridge has revealed that particular species of microbe found in the human gut can absorb PFAS, also known as ‘forever chemicals’.

PFAS do not break down easily in the environment or our bodies, meaning they accumulate over time and cause health problems, such as decreased fertility, developmental delays in children, and a higher risk of certain cancers and cardiovascular diseases.

The results are published in the journal Nature Microbiology.

First evidence of the critical role of the gut microbiome in removing PFAS

Scientists have identified a family of bacterial species, naturally found 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 ingested by the mice, which were then excreted in their feces.

Additionally, the scientists 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 chemicals.

The results are the first evidence of the role the gut microbiome plays in removing chemicals in mice.

The UK launched a parliamentary inquiry into forever chemicals

In the UK, there is increasing concern about the environmental and health impacts of PFAS, and as a result, the UK launched an inquiry into their risks and regulations.

Currently, there are over 4,700 PFAS chemicals in widespread use. Some are eliminated through urine, but others can persist in the body for many years.

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 the 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 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.”

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 gain notice because, at low levels, they’re not acutely toxic. But they’re like a slow poison.”