Abstract：
The theory of the brain-gut axis has confirmed that gut microbiota and metabolites are involved in the progression of neurodegenerative diseases through multiple pathways. However, few studies have highlighted the role of gut microbiota in cognitive impairment induced by aluminum (Al) exposure and its correlations with the homeostasis of essential metal content in the brain. To explore the relationship between alterations in the content of essential metals in the brain and relative abundance changes in gut microbiota induced by Al exposure, the Al, zinc (Zn), copper (Cu), iron (Fe), chromium (Cr), manganese (Mn), and cobalt (Co) content level in the hippocampus, olfactory bulb, and midbrain tissue were measured by inductively coupled plasma mass spectrometry (ICP-MS) methods after Al maltolate was intraperitoneally injected every other day for exposed groups. Then the unsupervised principal coordinates analysis (PCoA) and linear discriminant analysis effect size (LEfSe) were used to analyze the relative abundance of the gut microbiota community and the structure of the gut microbiome. Finally, the correlations between gut microbiota composition and essential metal content in the different exposure groups were explored by using the Pearson correlation coefficient method. Based on the results, we indicated that the content of Al in the hippocampus, olfactory bulb, and midbrain tissue was increased and then decreased with the increasing exposure duration, with peaks occurring between 14 and 30 days. Concomitantly, Al-exposure decreased the Zn, Fe, and Mn levels in these tissues. 16 S rRNA gene sequencing results indicated that significant differences in the intestinal microbial community structure at the phylum, family, and genus levels were found in the Day 90 exposed group compared with the Day 7 exposed group. Ten enriched species in the exposed group were identified as markers at the three levels. Furthermore, ten bacteria at the genus level were identified to have a significantly strong correlation (r = 0.70-0.90) with Fe, Zn, Mn, and Co.
摘要：
脑-肠轴理论已经证实，肠道微生物群和代谢物通过多种途径参与神经退行性疾病的进展。然而,很少有研究强调肠道菌群在铝（Al）暴露引起的认知障碍中的作用及其与大脑中必需金属含量稳态的相关性。探讨铝暴露引起的大脑中必需金属含量的变化与肠道菌群相对丰度变化之间的关系。Al,锌(Zn),铜(Cu),铁(Fe),铬(Cr),锰(Mn),海马中钴（Co）含量水平，嗅觉灯泡,暴露组每隔一天腹膜内注射苹果酸铝后，通过电感耦合等离子体质谱法（ICP-MS）测量中脑组织。然后利用无监督主坐标分析(PCoA)和线性判别分析效应大小(LEfSe)对肠道微生物群落的相对丰度和肠道微生物组的结构进行分析。最后,采用Pearson相关系数法探讨不同暴露组肠道菌群组成与必需金属含量的相关性。根据结果,我们表明海马中铝的含量，嗅觉灯泡,随着暴露时间的增加，中脑组织增加，然后减少，峰值出现在14到30天之间。同时，铝暴露减少了锌，Fe,和这些组织中的锰含量。16SrRNA基因测序结果表明,该门肠道微生物群落结构存在显著差异,家庭,与第7天暴露组相比，第90天暴露组发现了属和属水平。暴露组中的十个富集物种被鉴定为三个水平的标记。此外，在属水平上鉴定出10种细菌与Fe具有显着的强相关性（r=0.70-0.90），Zn,Mn,和公司。
