The general public’s awareness about the negative health impacts of environmental pollutants and chemicals is increasing. Microplastics, bisphenols (BPA, BPS, BPF), pesticides, toxic solvents like trichloroethylene, and PFAS are under greater scrutiny as research continues to link them to disease. When it comes to PFAS, there are proven links with certain cancers, changes to reproductive health, hormone disruption, and lowered immune function. In this article, we take a look at the links between PFAS exposure and gut health.
What are PFAS compounds?
PFAS stands for per- and polyfluoroalkyl compounds. These are man-made chemicals that have been used widely since the 1950s across all industries and in all sorts of consumer products. This was due to their desirable properties of being non-stick, stain-resisting, and water-repelling. PFAS chemicals degrade very slowly in the environment, and some PFAS compounds persist in the human body for decades. They also bioaccumulate in the environment, including in fish and marine species.
What is the association between PFAS and gut health?
PFAS are generally classified as endocrine-disrupting chemicals. These chemicals cause health problems because they so closely resemble hormones in the body. There is also strong evidence that PFAS causes inflammation.
One of the most comprehensive overviews of PFAS and human health was performed by the National Academies of Science, Engineering and Medicine (NASEM). They published a 300 page report on PFAS, in 2022. Among other things, they identified potential evidence for an increase in ulcerative colitis in adults as a result of PFAS exposure. But there have been other studies on PFAS and overall gut health.
Recent studies link PFAS with inflammatory bowel disease (IBD)
Today, there are an estimated 10 million people living with inflammatory bowel disease worldwide, including ulcerative colitis (UC) and Crohn’s Disease (CD). The incidence of IBD has increased steadily over time, with marked increases beginning in the 1950s, especially in industrialized countries. Some studies have suggested a link between environmental pollution, industrial chemicals, and increases in IBD.
Inflammation, ulcerative colitis, and IBD
As we already mentioned, a lot of research links PFAS with inflammation. Several studies have linked PFAS with inflammatory bowel disease (IBD). One in-depth study examined an entire community in Sweden that was adversely affected by PFAS pollution from aqueous film-forming foams (AFFF, the foam used in firefighting). This study found evidence for increased risk of Crohn’s disease.
Meanwhile, another study looked at longitudinal data from a study of military personnel with ulcerative colitis (UC) and Crohn’s disease (CD). It found that there was a clear correlation between increased levels of PFAS compounds and occurrence of both these diseases.
One of the most notorious PFAS compounds, PFOA, or perfluorooctanoic acid, has been classed as a proven human carcinogen by the IARC. PFOA has been phased out globally for the past 20 years. But due to its slow breakdown in the environment, it is still extremely widespread in blood samples. One study found evidence for higher levels of PFOA among UC patients than a control group.
Other ways PFAS impacts gut health
PFAS is a powerful surfactant, and this may be one of the triggers for inflammation. Other papers also suggest a link between PFAS and damage to the intestinal barrier. This could be linked to the way PFAS chemicals mimic fatty acids in the intestine. Either way, PFAS seems to be bad news for your gut health generally.
Gut microbiome changes
PFAS are proven to cause some kidney cancers. But the exact mechanisms were unclear until recently. A 2024 study may have found the missing link in an unexpected place: your gut microbiome. The study looked at PFAS and metabolites in the blood, as well as measuring bacteria in stool samples. The authors concluded that their proof of concept study:
“… provides the first evidence that reduced short-chain fatty acid-producing bacteria and anti-inflammatory metabolites may link PFAS exposure with impaired kidney function”
This was not the first study to suggest that PFAS may impact gut bacteria. A 2023 study also found that
“Significant alterations of gut-microbiota-related metabolites were induced by PFOA exposure, including bile acids and tryptophan metabolites such as 3-indoleacrylic acid and 3-indoleacetic acid”
Constipation
For several decades the CDC has run the National Health and Nutrition Examination Survey, known as NHANES. This mass surveillance study looks at a huge variety of factors that affect the health of the US population. Among other things, it looks at PFAS exposure and aspects relating to nutrition and overall health.
One paper used the NHANES dataset to investigate the link between PFAS exposure and constipation. The gut is a very sensitive organ and any disruption can have a profound effect on toilet habits. Interestingly, this paper actually found an inverse correlation between levels of PFAS and constipation. This suggests that there’s still a huge amount of research left to do on how PFAS impacts gut health.
Conclusions
Our understanding of the role PFAS chemicals play in gut health is just beginning to emerge. For those with gastrointestinal health issues such as ulcerative colitis, the link between high PFAS levels and UC is one potential reason to work on reducing PFAS exposures. Learn more about your PFAS levels using our at-home blood tests and take the first step in tracking your health.
Disclaimer: This article is for educational and informational purposes only. Nothing in this article or on the web site represents medical advice or an offer of medical, diagnostic, or treatment products or services. Anyone concerned about their health should consult a licensed medical professional.
