Intestinal flora variation reflects the short-term damage of microplastic to the intestinal tract in mice.

The potential toxicity of microplastic (MPs) to organisms has attracted extensive attention. However, due to the subacute toxicity of MPs, the biological effect is hard to verify in short-term exposure experiment. Here, by tracking the dynamics of gut microbes, mice model was utilized to evaluate the toxicity of compositional MPs (PE, PET, PP, PS and PVC). After 7 days digestive exposure, the physiological indicators were normal as the control group that the body weight and serum cholesterol levels were insignificant change. Whereas, through histopathological examination, all the treatment groups suffered colon tissue damage, among which PS had the most inflammatory cells. Moreover, the high-throughput sequencing results revealed great variation of intestinal flora in treated mice. The ratio of Bacteroidetes and Firmicutes in PE, PET and PP treatment groups heighten, and the relative abundance of Ruminococcaceae and Lachnospiraceae increased significantly at family levels. At the genus level, Alistipes bacteria in PS treatment group significantly decreased that is associated with obesity risk. It indicated that MPs induced inflammatory response would further interfere the dynamics of intestinal flora causing health effect in living organisms. This work shed light on MPs toxicity in short-term exposure and supplied research paradigm of MPs health risk assessment.