The effect of microplastic exposure on the distribution and metabolic pathways of gut microbiota in mice
Objective To observe the effect of microplastics on the distribution of intestinal microbiota in mice,and lay a foundation for further revealing the effects of microplastics on human health.Methods A mouse model consuming poly-styrene(PS)microplastics was established.Changes in blood glucose and lipid levels before and after microplastic feeding were detected.Metagenomic sequencing technology was used to detect and compare the intestinal flora species and differ-ences between the normal diet group(Control group)and the PS microplastics diet group(MPs group)to analyze the mech-anism of action of the effects of microplastics on the intestinal flora of mice.Results Compared with the Control group,at the phylum level,the relative abundance of Ascomycota significantly increased in the MPs group(t=-3.883,P=0.028);at the genus level,there was a significant increase in the relative abundance of Sphingomonas(t=—5.917,P=0.003),and a significant decrease in that of Weissella(t=-2.677,P=0.007);at the species level,there was a significant increase in the rel-ative abundance of Ralstonia mannitolilytica(t=-2.611,P=0.009)and a significant decrease in that of Lactobacillus john-sonii(t=-1.984,P=0.047);at the genus level,Massilistercora was positively correlated with LDL(P<0.001),while Ruthenibacterium,Phocaeicola and others were negatively correlated with TC(all P<0.010).Microplastics altered the rel-ative abundance of multiple metabolic pathways in normal mice,which may affect normal metabolic function.Conclusion The structural composition of normal mouse gut microbiota may be altered by microplastics within a certain range,and metabolic pathways may also be affected.The specific mechanisms need to be further studied.