A new study links toxic PFAS “forever chemical” exposure in young adults to reduced gut health, which researchers suspect is a driver of kidney disease later in life.
Kidney disease is one of the well-established health problems linked to PFAS exposure, and the new research suggests changes in gut bacteria and associated metabolites caused by the chemicals seems to be responsible for up to 50% of a decrease in kidney function seen over a four-year period.
“Along with these metabolic diseases comes a higher risk of diabetic or chronic kidney diseases, and this is one of the fastest-growing causes of mortality in the US, so it’s a really important question,” said Jesse Goodrich, one of the University of Southern California study’s co-authors.
PFAS, or per- and polyfluoroalkyl substances, are a class of about 15,000 compounds that are used to make products water, stain and grease resistant. They are also linked to a range of serious health problems like cancer, immune dysfunction, birth defects, endocrine disruption and liver disease. They are known as “forever chemicals” because they do not fully break down once in the environment.
The only US epidemiological study to check health impacts of PFAS found some of the chemicals probably cause chronic kidney disease. The researchers built on recent findings linking PFAS to gut health effects, and an increased understanding of how gut health is tied to kidney function.
To try to connect those dots, the scientists assembled a small cohort of young adults, a majority of whom were Hispanic, which is a group that has a high rate of metabolic diseases and a high kidney disease risk.
Researchers collected blood and stool samples that allowed them to measure PFAS levels, gut microbiome bacteria and circulating metabolites, then measured kidney function four years later. They found reductions in anti-inflammatory metabolites, as well as the bacteria that produce them, and increases in inflammatory metabolites.
That reduces kidney function, which down the line can increase the risk of the need for dialysis or a kidney transplant, especially if one has diabetes or another disease that affects the kidneys.
It is unclear why PFAS affect gut health, but Goodrich said a “working hypothesis” was that the chemicals mimic fatty acids that are essential to regulating gut health, and the compounds appear to throw off that process.
The study’s sample size was small, and researchers say it points to the need for a wider exploration of the issue. But the authors say the findings could lead to treatment for or prevention of kidney disease caused by PFAS exposure, which is difficult to manage.
At a policy level, the study underscores the need to reduce the amount of PFAS produced and released into the environment or used in consumer goods, said co-author Hailey Hampson. But if there is a significant exposure, then drugs that could be utilized to treat disease. The findings also suggest dietary interventions that balance gut bacteria could be useful, Hampson said.
