微塑料暴露对小鼠肠道菌群分布及代谢途径的影响

The effect of microplastic exposure on the distribution and metabolic pathways of gut microbiota in mice

目的研究微塑料对小鼠肠道菌群分布及代谢途径的影响,为进一步揭示微塑料对人类健康的影响奠定基础。方法建立食用聚苯乙烯(polystyrene,PS)微塑料的小鼠模型,检测微塑料喂饲前后小鼠血糖血脂的变化;利用宏基因组测序技术检测正常饮食小鼠和PS微塑料喂饲小鼠肠道菌群的种类和差异,分析微塑料对小鼠肠道菌群代谢的影响。结果与对照组相比,PS微塑料喂饲组小鼠血糖血脂水平无显著变化;在门水平上,子囊菌门相对丰度显著增加(t=-3.883,P=0.028);在属水平上,鞘氨醇单胞菌属相对丰度显著增加(t=-5.917,P=0.003),魏斯菌属相对丰度显著降低(t=-2.677,P=0.007);在种水平上,解甘露醇罗尔斯顿菌相对丰度显著增加(t=-2.611,P=0.009),约氏乳杆菌相对丰度显著降低(t=-1.984,P=0.047)。在属水平上,差异菌Massilistercora与LDL水平呈正相关(P<0.001),Ruthenibacterium、Phocaeicola等与TC水平呈负相关(均P<0.010);微塑料使正常小鼠多条代谢通路的相对丰度发生改变,可能会影响到正常代谢功能。结论微塑料在一定范围内能改变正常小鼠肠道菌群结构组成,同时可以改变小鼠代谢通路变化,具体机制有待深入研究。

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 polystyrene(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 differences between the normal diet group(Control group)and the PS microplastics diet group(MPs group)to analyze the mechanism 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 relative abundance of Ralstonia mannitolilytica(t=−2.611,P=0.009)and a significant decrease in that of Lactobacillus johnsonii(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 relative 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.