Study Finds Link Between PFAS and Kidney Problems Caused by Gut Bacteria

Findings come as chemical companies face thousands of lawsuits involving kidney cancer from PFAS exposure, which could be the result of damage to gut microbiomes.

Amid continuing concerns about the long-term health risks associated with exposure to “forever chemicals,” known as per- and polyfluoroalkyl substances (PFAS), new research suggests that the chemicals may increase the risk of kidney problems, due to their effect on microorganisms living in the gut microbiome.

More than 9,000 man-made chemicals are currently classified as PFAS, which have been widely used in numerous products over the past few decades to help resist grease, oil and water. While they are commonly found in non-stick pans, food packaging and other consumer products, the chemicals have also caused widespread water contamination in communities throughout the U.S., due to high levels of PFAS in aqueous film-forming foam (AFFF), which have been used by civilian and military firefighters to combate petroleum fires.

The chemicals are known to persist in the environment and build up in the human body. As a result, researchers have linked PFAS exposure to an increasing number of serious health consequences in recent years, including kidney cancer, testicular cancer, ulcerative colitis and other serious diseases.

PFAS Exposure and Gut Health

In a new study published in the December issue of Science of the Total Environment, researchers indicate that they may have an explanation for the link between PFAS and kidney problems, indicating that the chemicals may have negative effects on gut bacteria, which may lead to kidney function loss.

Gut microbiomes include a community of bacterial species that live in the digestive tract, which help regulate digestion. The gut bacteria play a key role in the immune system, and some believe they can affect other processes in the body as well.

While past studies have already linked PFAS exposure to lower kidney function, researchers have never determined what mechanism of action links the two factors.

For the new study, University of California researchers conducted a longitudinal cohort examination involving 78 young adults between the ages of 17 and 22 who participated in the Southern California Children’s Health Study. They looked at several types of PFAS and gut bacteria, determining types and concentrations.

According to the findings, the higher the amount of PFAS concentrations in the body, the lower the person’s kidney function four years later. The researchers determined that more than 50% of the loss of function was caused by changes in the gut bacteria and related metabolites, likely due to PFAS exposure.

“Our proof-of-concept analysis provides the first evidence that reduced short-chain fatty acid-producing bacteria and anti-inflammatory metabolites may link PFAS exposure with impaired kidney function,” the researchers concluded. “This study raises the possibility of future targeted interventions that can alter gut microbiome or circulating metabolite profiles to prevent PFAS induced kidney damage.”

PFAS Exposure Lawsuits

As studies have been published in recent years about the side effects associated with PFAS chemicals, a growing number of lawsuits have been filed against 3M Company, DuPont, Chemguard, Tyco Fire Products and other manufacturers of PFAS chemicals and fire safety products that released large volumes of the toxic chemicals into the environment and local water supplies, particularly around military bases, airports and firefighter training locations.

The litigation includes thousands of PFAS water contamination lawsuits brought by local water providers and individuals diagnosed with various types of cancer, as well as firefighter cancer lawsuits brought by individuals who came into direct contact with the chemicals while using AFFF products.

Many of the lawsuits raised allegations that there was a link between exposure to PFAS and kidney problems, often involving a diagnosis of kidney cancer. However, other lawsuits allege that individuals exposed to the chemicals developed testicular cancer, liver cancer, thyroid cancer, thyroid disease, ulcerative colitis and several other injuries.

Given common questions of fact and law raised in PFAS injury and exposure lawsuits brought throughout the federal court system, the litigation has been consolidated under U.S. District Judge Richard M. Gergel in South Carolina, for coordinated pretrial proceedings as part of an MDL, or multidistrict litigation.

As part of the coordinated management of the claims, a small group of early PFAS exposure lawsuits are being prepared for trial dates starting in 2025, involving claims that individuals developed injuries after drinking water known to be contaminated with high levels of the chemicals.

While the outcome of these early trial dates will not have any binding impact on other claims being pursued throughout the federal court system, they are designed to help gauge how juries may respond to certain evidence and testimony that will be repeated throughout the litigation.