Human gut bacteria bioaccumulate per- and polyfluoroalkyl substances

Area of Science:

• Environmental Science
• Microbiology
• Toxicology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants with significant health concerns.
• The interaction of PFAS with human gut bacteria remains largely unknown, despite their prevalence in the human microbiome.

Purpose of the Study:

• To investigate the bioaccumulation capacity of human gut bacteria for PFAS.
• To understand the mechanisms and implications of PFAS interaction with gut microbiota.

Main Methods:

• Screening of 38 gut bacterial strains for PFAS bioaccumulation.
• Utilizing cryogenic focused ion beam secondary-ion mass spectrometry (cryo-FIB-SEM) for intracellular localization.
• Employing proteomic, metabolomic, and mouse colonization models to assess PFAS impact and transport.

Main Results:

• Demonstrated significant PFAS bioaccumulation across 38 gut bacterial strains, with some reaching millimolar intracellular concentrations.
• Identified active transmembrane transport mechanisms in Escherichia coli, enhanced by the absence of the TolC efflux pump.
• Confirmed intracellular PFNA localization in E. coli and observed higher PFNA levels in faeces of mice colonized with human gut bacteria.

Conclusions:

• Gut bacteria possess a substantial capacity for bioaccumulating PFAS, challenging previous assumptions.
• Findings highlight the potential role of gut microbiota in the fate and transport of PFAS within the human body and the environment.