Certain Gut Microbes Found to Absorb Ingested PFAS: Study

Our gut bacteria — collectively known as the “gut microbiome” — perform many important tasks in addition to the basics of breaking down food and vitamins, including supporting our immune system and brain health.

Researchers from the University of Cambridge have recently identified a family of gut bacteria that can absorb per- and polyfluoroalkyl substances (PFAS) “forever chemicals” from their surroundings. They said boosting these bacteria in our gut could help safeguard us from PFAS’ harmful effects.

“Per- and polyfluoroalkyl substances (PFAS) are persistent pollutants that pose major environmental and health concerns. While few environmental bacteria have been reported to bind PFAS, the interaction of PFAS with human-associated gut bacteria is unclear. Here we report the bioaccumulation of PFAS by 38 gut bacterial strains,” the authors of the study wrote. “[M]ice colonized with human gut bacteria showed higher PFNA levels in excreted faeces than germ-free controls or those colonized with low-bioaccumulating bacteria. Together, our findings uncover the high PFAS bioaccumulation capacity of gut bacteria.”

When nine of the species from the human gut bacteria family were introduced into mice microbiomes, they rapidly accumulated ingested PFAS, which were afterward excreted in feces, the press release said.

PFAS have been associated with a variety of health concerns, including increased risk of certain cardiovascular diseases and cancer, developmental delays in children and decreased fertility.

Ubiquitous in the modern world, PFAS are difficult to avoid, as they are used in everyday items such as nonstick cookware, waterproof clothing, food packaging and cosmetics for their resistance to water, heat, oil and grease.

“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,” said co-author of the study Dr. Indra Roux, a researcher at the University of Cambridge’s MRC Toxicology Unit, in a press release from the university.

Researchers in the Patil Lab have discovered that certain species of gut bacteria can absorb PFAS. Boosting these species in our gut microbiome could be a new way to protect us from the harmful effects of PFAS. Read more here: buff.ly/4FsVFsS @kiranrpatil.bsky.social @indraroux.bsky.social

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— MRC Toxicology Unit (@mrc-tu.bsky.social) July 1, 2025 at 5:02 AM

The researchers found that the microbes worked harder as levels of PFAS increased, consistently removing the same amount of the toxic substances. The bacterial species they tested were able to absorb from 25 to 74 percent of PFAS within minutes of exposure.

The results of the study are the first evidence that the gut microbiome has the potential to help remove PFAS from our bodies, though it has yet to be tested directly in humans.

The research team plans to use the discovery to make probiotic dietary supplements to boost levels of the helpful microbes in the human gut.

“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,” said senior author of the study Dr. Kiran Patil, director of research at the University of Cambridge’s MRC Toxicology Unit, in the press release. “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.”

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More than 4,700 PFAS are currently in widespread use, and there is growing concern about their environmental and health impacts. In April, the United Kingdom Parliament launched an inquiry into the risks and regulation of PFAS forever chemicals.

Some of the dangerous chemical compounds get cleared from the human body through the urine within days, but others can stay for years due to their longer molecular structure.

“We’re all being exposed to PFAS through our water and food – these chemicals are so widespread that they’re in all of us,” said first author of the study Dr. Anna Lindell, a researcher at the University of Cambridge’s MRC Toxicology Unit, in the press release.

While we wait for probiotics to be developed, the researchers said the best ways to protect ourselves from PFAS are to use a high-quality water filter and avoid cookware coated with PFAS.

“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 said.

The results of the study, “Human gut bacteria bioaccumulate per- and polyfluoroalkyl substances,” were published in the journal Nature Microbiology.