The Role of Gut Microbiota and Untargeted Metabolomics in Pfas Mixture Exposure-Induced Depression-Like Behavioral Alterations in C57bl/6j Mice: A Mechanistic Study

Abstract

This study aimed to investigate the effects of per- and polyfluoroalkyl substances (PFAS) mixture exposure on depression-like behaviors in C57BL/6J mice and elucidate the underlying mechanisms through the gut microbiota-gut-brain axis and untargeted metabolomics. Male mice were subjected to a chronic unpredictable mild stress (CUMS) model combined with oral gavage of PFAS (PFBS 35 mg/kg, PFBA 15 mg/kg, PFHxA 1 mg/kg) for six weeks. Behavioral tests (Morris Water Maze, Forced Swimming Test, Open Field Test) revealed that PFAS exposure significantly ameliorated CUMS-induced depressive-like behaviors. Transmission electron microscopy demonstrated mitochondrial damage in hippocampal neurons in CUMS mice, which was alleviated by PFAS intervention. Gut microbiota analysis showed CUMS-induced depletion of anti-inflammatory genera Dubosiella and Allobaculum and enrichment of pro-inflammatory Eubacterium_xylanophilum, while PFAS exposure partially reversed these dysbiotic trends. Metabolomic profiling identified abnormal elevations of hypothalamic pro-inflammatory metabolites (5-HETE, 12-HETE) and serum sphingosine in CUMS mice, which were normalized by PFAS treatment. Integrated multi-omics analysis highlighted key pathways, including arachidonic acid metabolism, serotonergic synapses, and TRP channel regulation, with Dubosiella and Allobaculum negatively correlating with hypothalamic 5-HETE and positively with serum trimethylamine N-oxide (TMAO). Mechanistically, PFAS mitigated depressive behaviors by suppressing NF-κB/TRP pathway-driven neuroinflammation, maintaining gut microbial homeostasis, and restoring metabolic balance. These findings underscore the role of PFAS in modulating the microbiota-gut-brain axis and provide insights into environmental chemical contributions to neuropsychiatric disorders.

Note:
Funding declaration: This work was supported by Guang Xi Natural Science Foundation of China (2023GXNSFAA026035) and Natural Science Foundation of China (81402711) under Grant.

Conflict of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical Approval: The protocol obtained approval from the Animal Experimentation Ethics Committee of Guilin Medical College(GLMC-IACUC-20251019) .

Keywords: Per- and polyfluoroalkyl substances, Depression, Transcriptome, Gut microbiota, metabolomics