Certain species of microbe found in the human gut can absorb PFAS (Jul 2025) Human gut bacteria bioaccumulate per- and polyfluoroalkyl substances Study

[Michael Harrop]

• https://phys.org/news/2025-06-species-microbe-human-gut-absorb.html
• https://www.cam.ac.uk/research/news/gut-microbes-could-protect-us-from-toxic-forever-chemicals
• https://www.nature.com/articles/s41564-025-02032-5

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 'humanize' the mouse microbiome, the bacteria rapidly accumulated PFAS eaten by the mice, which were then excreted in feces.

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.

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Abstract​

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 ranging in concentration from nanomolar to 500 μM. Bacteroides uniformis showed notable PFAS accumulation resulting in millimolar intracellular concentrations while retaining growth. In Escherichia coli, bioaccumulation increased in the absence of the TolC efflux pump, indicating active transmembrane transport. Cryogenic focused ion beam secondary-ion mass spectrometry confirmed intracellular localization of the PFAS perfluorononanoic acid (PFNA) in E. coli. Proteomic and metabolomic analysis of PFNA-treated cells, and the mutations identified following laboratory evolution, support these findings.

Finally, mice 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.

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