Polystyrene may alter the cooperation mechanism of gut microbiota and immune system through co-exposure with DCBQ.

The toxicity of Polystyrene (PS) may be higher through co-exposure with other pollutants. Human can simultaneously face the challenges from the various pollutants. Nevertheless, little research has been done on the combined effects of PS and 2,6-dichloro-p-benzoquinone (DCBQ) disinfection byproduct. Considering the potential risk of PS and DCBQ, we aimed to illustrate the effects of PS in combination with DCBQ on the immune responses of mice. We found that cotreatment of DCBQ and PS may inhibit the activity of spleen CD4+ T cells and interfere with the normal function of the immune system. Further research found that DCBQ + PS resulted in increasing amount of the inflammatory cells in intestine via histopathological evaluation. The reason might be that DCBQ + PS has changed the composition of intestinal flora, abnormally activated intestinal macrophage, and inhibited the expression of immune-related genes, thus leading to intestinal immune disorders and triggering intestinal inflammation. In summary, PS may alter the cooperation mechanism of gut microbiota and immune system through co-exposure with DCBQ. Current results suggested that more attention should be paid to the combined toxic effects of environmental contaminants.