New research from a team at the Keck School of Medicine of USC has revealed that the connection between per- and polyfluoroalkyl substances, or PFAS, and kidney damage may be tied to dysregulation of the gut microbiome.
According to the study published in Science of The Total Environment, researchers analyzed data from 78 participants ages 17 to 22 enrolled in the Southern California Children’s Health Study, a large-scale longitudinal effort to understand the effects of pollution on health. Fifty-six percent of the sample was Hispanic, a group that faces an outsized risk for chronic kidney disease.
At baseline, the researchers collected blood and stool samples that allowed them to measure PFAS exposure, gut microbiome bacteria and circulating metabolites. At a follow-up appointment four years later, the researchers collected a second round of data on kidney function.
They found that when PFAS exposure increased by one standard deviation, kidney function was 2.4% worse at the follow-up visit. The researchers then performed a statistical analysis to determine whether a third factor—gut bacteria and related metabolites—contributed to that association.
The analysis revealed two separate groups of bacteria and metabolites that helped explain the effect of PFAS exposure on kidney function. One group explained 38% of the change in kidney function, and one group explained 50% of the change. Both groups of bacteria and metabolites performed beneficial activities, such as lowering inflammation in the body, that were hindered when PFAS exposure went up.
The findings, which add to other Keck School of Medicine studies of PFAS, including longitudinal research, offer early clues about how to protect the kidneys from PFAS-related damage.
“Our findings are an important piece of the puzzle about the many different health risks of PFAS, which can provide policymakers with information that helps them develop policies to protect the public from exposure to these chemicals,” said Jesse Goodrich, PhD, an assistant professor of population and public health sciences at the Keck School of Medicine and senior author of the study.
Next, the research team will move beyond measuring metabolites in the blood to detecting their presence in specific body tissues, including in the kidneys.