Certain gut microbes have been discovered to absorb toxic PFAS “forever chemicals” and help eliminate them from the body through feces, according to new research from the University of Cambridge.
This is encouraging news, especially since current methods for reducing harmful PFAS levels in the body are limited to bloodletting and a cholesterol medication that can cause unpleasant side effects.
The study found that these microbes could remove as much as 75% of some PFAS from the digestive systems of mice. Some of the researchers are looking to create probiotic supplements that could enhance beneficial microbes in the human gut, potentially lowering PFAS levels.
“If we could harness this for humans by developing probiotics, it might provide a more pleasant solution with fewer side effects,” noted Anna Lindell, a doctoral student and co-author of the study.
PFAS refers to a category of around 15,000 compounds commonly used to make products resistant to water, stains, and grease. They have been associated with serious health issues, including cancer, birth defects, and immune system problems. Dubbed “forever chemicals,” they don’t naturally decompose in the environment.
The US Environmental Protection Agency has determined that no level of PFOS or PFOA, two widely known PFAS compounds, is safe in drinking water. Their half-life in human blood ranges from two to five years, indicating it could take decades for the body to fully eliminate PFAS naturally.
Although this study is the first to showcase gut microbes expelling PFAS, these microbes have previously shown potential in mitigating other contaminants, such as microplastics.
The researchers initially aimed to examine a variety of common food contaminants without specifically focusing on PFAS. In fact, there are no established PFAS limits for food in the US, yet it is widely recognized as a primary exposure pathway.
By concentrating on microbes that excelled in expelling PFAS, the study’s authors examined nine bacterial species introduced into mice to mimic a human microbiome. These bacteria quickly accumulated and absorbed the PFAS consumed by the mice, which were subsequently excreted.
The bacteria appear to absorb the chemicals and then utilize a mechanism to pump out toxins, aiding in their excretion. While the precise way this absorption happens is still unclear, Lindell suspects there might be a similar mechanism used by other microbes to expel various contaminants, drugs, or antibiotics.
The microbes primarily targeted larger, more harmful “long-chain” PFAS, such as PFOA and PFNA, expelling them at rates of up to 58% and 74%, respectively. In contrast, shorter “short-chain” PFAS are generally processed out of the body more efficiently through urine.
Lindell, along with other study leaders, has founded a company called Cambiotics to advance their probiotic development based on these findings. They plan to follow this research with a human study.
However, Lindell emphasized that this probiotic shouldn’t be seen as a solution to the wider PFAS issue: “This shouldn’t be an excuse to overlook other sustainable solutions or to ignore the larger PFAS problem.”
