A bacterium that already lives in most people’s intestines can latch onto per- and polyfluoroalkyl substances and escort them out of the body through the digestive tract, according to a study published in Nature Microbiology in May 2026. Researchers at the University of Cambridge report that one species, Bacteroides uniformis, pulled roughly 50 percent of a common PFAS compound out of solution within minutes during laboratory assays. The effect also held up in mice colonized with human gut microbes, raising the prospect that the body’s own bacteria could one day be enlisted to lower the chemical load that federal biomonitoring has detected in nearly all Americans.
What the experiments showed
The Cambridge team screened multiple strains of human gut bacteria and found that several could bioaccumulate PFAS, absorbing the synthetic molecules into their cells without breaking them down. B. uniformis stood out. In controlled assays, it sequestered about 50 percent of PFNA, a nine-carbon PFAS compound, across a wide range of exposure concentrations. Some runs recorded uptake in fewer than three minutes. Longer-chain PFAS variants were absorbed more readily than shorter ones, consistent with how these fluorinated molecules interact with biological membranes.
“These bacteria act like sponges for PFAS,” said Dr. Kiran Patil, the study’s senior author and a professor of systems biology at Cambridge, in the university’s news release. The team then moved to animal models: mice whose guts had been populated with human-derived microbes. In those animals, the bacteria bound PFAS inside the living digestive system and the chemicals were excreted in feces, demonstrating that the sequestration seen in test tubes could function in a real gut environment.
The work builds on a principle Patil’s group established in a 2021 study published in Nature, which showed that gut bacteria can absorb common pharmaceutical drugs into their cells without metabolizing them. That earlier finding proved intestinal microbes act as passive sinks for foreign compounds. The new results extend the concept from therapeutic drugs to persistent environmental pollutants.
Why PFAS body burden matters
PFAS are called “forever chemicals” because their carbon-fluorine bonds resist virtually all natural degradation. Manufactured since the 1940s for use in nonstick coatings, water-resistant fabrics, and firefighting foams, they have spread into drinking water, soil, and the food supply worldwide. Once inside the body, certain PFAS compounds can persist for years. PFOS, one of the most studied variants, has an estimated half-life in human blood of roughly four to five years, according to data reviewed by the Agency for Toxic Substances and Disease Registry.
Epidemiological research has linked elevated PFAS exposure to increased cholesterol, thyroid disruption, reduced vaccine response in children, and certain cancers, though establishing direct causation remains difficult. The U.S. Centers for Disease Control and Prevention tracks population-level exposure through the National Report on Human Exposure to Environmental Chemicals, which has consistently found measurable PFAS concentrations in blood samples from a nationally representative cross-section of Americans. The CDC notes that detecting a chemical in blood does not by itself prove harm, but the sheer ubiquity of exposure is what drives scientific interest in strategies to reduce body burden.
What has not been proven yet
No human clinical trial has tested whether boosting Bacteroides uniformis or related strains in a person’s gut actually lowers circulating PFAS levels. The published evidence stops at controlled lab assays and humanized-mouse models. Bridging that gap would require pharmacokinetic studies showing that serum PFAS half-life drops measurably when high-bioaccumulating strains are introduced or expanded in a human intestine. That data does not yet exist.
The mechanism itself raises practical questions. Because the bacteria absorb PFAS without chemically destroying it, the strategy depends on continuous removal: microbes grab the chemicals, carry them through the colon, and leave the body in stool. Whether that process can outpace the rate at which new PFAS enters through contaminated food and water is unknown. Any biological removal approach would need to work at a scale and speed that makes a meaningful dent in total body burden over months or years.
There is also the question of delivery. The Cambridge team found that sequestration ability varies across bacterial species and across different PFAS chain lengths. Whether a future probiotic product could deliver enough of the right organisms, in the right gut conditions, to produce a clinical benefit is speculative. Existing approaches to lowering PFAS levels in the body are limited. Some research has explored blood or plasma donation as a way to accelerate clearance, and the bile acid sequestrant cholestyramine has been investigated in small studies, but neither is an established treatment. The bacterial route is, for now, one more hypothesis awaiting human evidence.
Where the research goes from here
The Nature Microbiology paper provides quantified uptake rates, chain-length comparisons, and animal-model validation, all generated under controlled conditions and subjected to formal peer review. A preprint version of the work appeared on bioRxiv before publication, allowing outside scientists to scrutinize the data during the revision process.
The next steps, according to the Cambridge release, involve identifying the molecular machinery that allows B. uniformis to absorb PFAS so efficiently and exploring whether engineered or naturally selected strains could improve performance. Human intervention trials would be the critical milestone, but designing them will require answering basic questions first: what dose of bacteria, delivered how often, in what formulation, and measured against which PFAS endpoints in blood.
For now, the study offers a proof of concept rather than a remedy. It shows that biology already has a partial answer to a chemical problem that engineering alone has struggled to solve, and that the answer may have been living in the human gut all along. Whether scientists can turn that biological quirk into something people actually benefit from is the work that comes next.
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*This article was researched with the help of AI, with human editors creating the final content.
