Distinctive metabolic disturbances associated with redox homeostasis, nervous and hormonal functions during gut microbial enrichment upon polystyrene microplastic exposure

Microplastic-induced gut microbial enrichment was dominated by bacteria within Eubacteriales, correlated with the virome, and accompanied by colitis. The polyamine synthetic pathway was activated to maintain glutathionylspermidine homeostasis, concurrent with decreases in pathways involved in the production of energy and reactive oxygen species under microplastic exposure. Tryptophan-serotonin, phenylalanine-phenylethylamine, and tyrosine-thyroxine pathways increased, whereas tryptophan-kynurenine, tryptophan-indole, and tyrosine-tyramine pathways decreased under microplastic exposure. Enterolactone synthesis and cholesterol-derived hormone synthesis were increased under microplastic exposure. Bacteria within Eubacteriales (e.g., Oscillospiraceae bacterium and Clostridiales bacterium) contributed most to metabolic disturbances under microplastic exposure.