CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Mater Chem B. 2023 Mar 1;11(9):1904-1915. doi: 10.1039/d2tb02756a.
Due to their excellent antibacterial ability, silver nanomaterials (Ag NMs) are the most frequently used nanomaterials. Their widespread use introduces the risk of human ingestion. However, the potential toxicity of Ag NMs to the gut microbiota and their metabolic profile are yet to be fully explored. In this study, we examined the effects of Ag NMs after oral administration (0.5 mg kg and 2.5 mg kg, 14 and 28 days) on gut homeostasis by integrating tissue imaging, 16s rRNA gene sequencing and metabolomics techniques. We uncovered that silver nanoparticles (Ag NPs) and silver nanowires (Ag NWs) altered the structure (inhibiting the proliferation of Gram-negative bacteria) and decreased the diversity of gut microbiota in mice after short-term (14 days) exposure, while the microbial community tended to recover after long-term exposure (28 days), indicating that the resistance and resilience of the gut microbiome may pose a defense against the interference by reactive, exogenous nanomaterials. Interestingly, even though the gut microbiota structure recovered after 28 days of exposure, the gut metabolites significantly changed, showing increased 1-indole-3-carboxylic acid and elevated levels of 5-HT in the gut and blood. Collectively, our results provide a piece of evidence on the association between the ingestion of exogenous nanoparticles and gut homeostasis, especially the metabolic profile of the host. This work thus provides additional insights for the continued investigation of the adverse effects of silver nanomaterials on biological hosts.
由于其出色的抗菌能力，银纳米材料（Ag NMs）是最常使用的纳米材料。它们的广泛使用引入了人类摄入的风险。然而，Ag NMs 对肠道微生物群及其代谢谱的潜在毒性尚未得到充分探索。在这项研究中，我们通过整合组织成像、16s rRNA 基因测序和代谢组学技术，研究了口服（0.5mgkg 和 2.5mgkg，14 天和 28 天）Ag NMs 对肠道稳态的影响。我们发现，银纳米颗粒（Ag NPs）和银纳米线（Ag NWs）在短期（14 天）暴露后改变了肠道微生物群的结构（抑制革兰氏阴性菌的增殖）并降低了其多样性，而微生物群落在长期（28 天）暴露后趋于恢复，表明肠道微生物组的抗性和弹性可能对反应性外源性纳米材料的干扰构成防御。有趣的是，即使在暴露 28 天后，肠道微生物群结构恢复，但肠道代谢物明显发生变化，表现为肠道和血液中 1-吲哚-3-羧酸和 5-HT 水平升高。总的来说，我们的研究结果提供了关于外源性纳米颗粒摄入与肠道稳态之间关联的证据，特别是宿主的代谢谱。这项工作为进一步研究银纳米材料对生物宿主的不良影响提供了更多的见解。
