纳米塑料-重金属-塑化剂联合暴露对儿童肠道微生物菌群及代谢的影响

Effect of combined exposure of nanoplastics-heavy metal-plasticizer on gut microbiota and metabolism in children

[目的]探究纳米塑料(NPs)、镉(Cd)和邻苯二甲酸二丁酯(DBP)污染对儿童肠道菌群多样性、氨基酸代谢及短链脂肪酸(SCFAs)含量的影响.[方法]利用16S rRNA高通量测序技术和高效液相色谱-质谱法LC-MS/MS分析NPs、Cd、DBP单一污染及纳米塑料聚丙烯(PP)、Cd、DBP复合污染对儿童肠道细菌群落及肠道微生物代谢产物中短链脂肪酸及氨基酸含量的变化.[结果]高通量检测结果显示,与对照相比,在门属水平上,单一污染的优势菌门属无明显变化,PP+Cd、PP+DBP+Cd复合污染优势菌门属水平丰富度与多样性显著下降;LC-MS/MS检测结果显示,在肠道微生物代谢产物中,经NPs与DBP暴露后,氨基酸含量呈现不同程度的下降,而Cd、PP+Cd、PP+Cd+DBP处理后,大多数氨基酸的含量显著增加;同时检测到丁酸、戊酸的含量也发生变化.[结论]与单一污染物处理相比NPs相关复合污染物暴露处理后其肠道微生物紊乱程度更强,且不同污染物处理均会影响肠道微生物的氨基酸代谢和SCFAs产量.肠道菌群与人体健康密切相关,探究肠道菌群及代谢功能在NPs、Cd、DBP影响下的变化,从肠道菌群层面评价NPs、Cd、DBP单一暴露和复合暴露污染下的危害和风险具有重要意义.

[Objective]To explore the effects of nano-plastics(NPs),cadmium(Cd)and dibutyl phthalate(DBP)on intestinal flora diversity,amino acid metabolism and short-chain fatty acid content in children.[Methods]The effects of single and combined pollution of nano-plastics(polypropylene,PP),Cd and DBP on the contents of short-chain fatty acids and amino acids in intestinal bacterial communities and intestinal microbial metabolites in children were analyzed by high throughput sequencing technology of 16S rRNA and high performance liquid chromatogen-mass spectrometry(LC-MS/MS).[Results]The high-throughput test results showed that,compared with the control,at the phylum genus level,the dominant bacteria with single pollution had no significant change,and the diversity of the dominant bacteria with PP+Cd,PP+DBP+Cd combined pollution significantly decreased.The results of LC-MS/MS test showed that the amino acid content of intestinal microbial metabolites decreased to varying degrees after exposure to NPs and DBP,while the content of most amino acids increased significantly after Cd,PP+Cd,PP+Cd+DBP treatment.The content of butyric acid and valerate also changed.[Conclusion]Compared with the single pollutant treatment,the intestinal microbial disorder is stronger after exposure to nano-plastics-related complex pollutants,and different pollutant treatments could affect the amino acid metabolism and SCFAs production of intestinal microorganisms.Intestinal flora is closely related to human health.It is of great significance to explore the changes of intestinal flora and metabolic function under the influence of NPs,Cd and DBP,and to evaluate the hazards and risks of single exposure and combined exposure to NPs,Cd and DBP from the level of intestinal flora.