Gut Microbiota Participates in Polystyrene Microplastics-Induced Hepatic Injuries by Modulating the Gut-Liver Axis

Dietarypollution by polystyrene microplastics (MPs)can causehepatic injuries and microbial dysbiosis. Epigallocatechin-3-gallate(EGCG), the major polyphenol in green tea, exerts beneficial effectson the liver by modulating the gut microbiota. However, the role ofmicrobiota in MPs-induced hepatic injuries and the protective effectof EGCG have not been clarified. Here, 5 & mu;m MPs were orallyadministered to mice to induce hepatic injuries. Subsequently, antibioticcocktail (ABX) and fecal microbial transplant (FMT) experiments wereperformed to investigate the underlying microbial mechanisms. Additionally,EGCG was orally administered to mice to explore its protection againstMPs-induced hepatic injuries. Our results showed that MPs activatedsystemic and hepatic inflammation, promoted fibrosis, and alteredthe liver metabolome; meanwhile, MPs damaged the gut homeostasis bydisturbing the gut microbiome, promoting colonic inflammation, andimpairing the intestinal barrier. Notably, MPs reduced the abundanceof the probiotics Akkermansia, Mucispirillum, and Faecalibaculum whileincreasing the pathogenic Tuzzerella. Interestingly, the eliminationof gut microbiota mitigated MPs-induced colonic inflammation and intestinalbarrier impairment. Moreover, ABX ameliorated MPs-induced systemicand hepatic inflammation but not fibrosis. Correspondingly, microbiotafrom MPs-administered mice induced colonic, systemic, and hepaticinflammation, while their profibrosis effect on the liver was notobserved. Finally, EGCG elevated the abundance of probiotics and effectivelyrepressed MPs-induced colonic inflammation. MPs-induced systemic andhepatic inflammation, fibrosis, and remodeling of the liver metabolomewere also attenuated by EGCG. These findings illustrated that gutmicrobiota contributed to MPs-induced colonic and hepatic injuries,while EGCG could serve as a potential prevention strategy for theseadverse consequences.

Automated summary

Dietary pollution by polystyrene microplastics (MPs) can cause hepatic injuries and microbial dysbiosis. EGCG, the major polyphenol in green tea, has a protective effect on liver by modulating the gut microbiota. However, the mechanisms underlying MPs-induced hepatic injuries and the protective effect of EGCG are still not fully understood.