Human Intestinal Microbiota Composition Shapes Model Polyfluoroalkyl Substance Biotransformation.

Area of Science:

• Environmental Science
• Microbiology
• Toxicology

Background:

• 6:2 polyfluoroalkyl phosphate diester (6:2 diPAP) is a common environmental contaminant with human exposure.
• Environmental microbes and the human gut microbiome can biotransform related compounds.
• The variability of polyfluoroalkyl phosphate diester (PAP) biotransformation by the human gut microbiome is not well understood.

Purpose of the Study:

• To investigate the in vitro biotransformation of 6:2 diPAP by the human gut microbiome across six different cohorts.
• To explore the relationship between microbial community composition and the resulting perfluoroalkyl acid (PFAA) profiles.
• To assess the variability in 6:2 diPAP biotransformation pathways.

Main Methods:

• Utilized gas chromatography mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS) to analyze biotransformation products.
• Employed 16S rRNA amplicon sequencing to characterize microbial community composition.
• Incubated 6:2 diPAP with gut microbiome samples from six distinct cohorts (A-F).

Main Results:

• All tested cohorts demonstrated the biotransformation of 6:2 diPAP.
• Significant differences in downstream perfluoroalkyl acid (PFAA) profiles were observed among cohorts, indicating diverse metabolic pathways.
• Microbial community analysis revealed that initial community composition, potentially driven by low-abundance taxa, influenced the transformation products.

Conclusions:

• The human gut microbiome exhibits variable pathways for biotransforming 6:2 diPAP.
• Gut microbiome composition plays a crucial role in determining the products of polyfluoroalkyl substance (PFAS) transformation.
• Further mechanistic studies are needed to identify the specific microbial genes and pathways involved in PFAS gut biotransformation.