Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Biomedical Informatics, Center for Clinical and Translational Sciences, University of Alabama at Birmingham, Birmingham, AL, USA.
Geroscience. 2018 Jun;40(3):257-268. doi: 10.1007/s11357-018-0026-y. Epub 2018 Jun 5.
Advanced age has been associated with alterations to the microbiome within the intestinal tract as well as intestinal permeability (i.e., "leaky gut"). Prior studies suggest that intestinal permeability may contribute to increases in systemic inflammation-an aging hallmark-possibly via microorganisms entering the circulation. Yet, no studies exist describing the state of the circulating microbiome among older persons. To compare microbiota profiles in serum between healthy young (20-35 years, n = 24) and older adults (60-75 years, n = 24) as well as associations between differential microbial populations and prominent indices of age-related inflammation. Unweighted Unifrac analysis, a measure of β-diversity, revealed that microbial communities clustered differently between young and older adults. Several measures of α-diversity, including chao1 (p = 0.001), observed species (p = 0.001), and phylogenetic diversity (p = 0.002) differed between young and older adults. After correction for false discovery rate (FDR), age groups differed (all p values ≤ 0.016) in the relative abundance of the phyla Bacteroidetes, SR1, Spirochaetes, Bacteria_Other, TM7, and Tenericutes. Significant positive correlations (p values ≤ 0.017 after FDR correction) were observed between IGF1 and Bacteroidetes (ρ = 0.380), Spirochaetes (ρ = 0.528), SR1 (ρ = 0.410), and TM7 (ρ = 0.399). Significant inverse correlations were observed for IL6 with Bacteroidetes (ρ = - 0.398) and TM7 (ρ = - 0.423), as well as for TNFα with Bacteroidetes (ρ = - 0.344). Similar findings were observed at the class taxon. These data are the first to demonstrate that the richness and composition of the serum microbiome differ between young and older adults and that these factors are linked to indices of age-related inflammation.
高龄与肠道内微生物组的改变以及肠道通透性（即“肠漏”）有关。先前的研究表明，肠道通透性可能通过微生物进入循环系统而导致全身性炎症增加——这是衰老的一个标志。然而，目前尚无研究描述老年人循环微生物组的状态。本研究旨在比较健康的年轻（20-35 岁，n=24）和老年人（60-75 岁，n=24）血清中的微生物组谱，并探讨差异微生物群与与年龄相关炎症的显著指标之间的关系。非加权 UniFrac 分析是一种β多样性的度量方法，结果显示微生物群落在年轻和老年人之间聚类不同。几种α多样性的度量方法，包括 chaol（p=0.001）、观察到的物种（p=0.001）和系统发育多样性（p=0.002）在年轻和老年人之间存在差异。经错误发现率（FDR）校正后，两组在厚壁菌门、SR1、螺旋体门、细菌其他、TM7 和无壁菌门的相对丰度上存在差异（所有 p 值均≤0.016）。经 FDR 校正后，IGF1 与厚壁菌门（ρ=0.380）、螺旋体门（ρ=0.528）、SR1（ρ=0.410）和 TM7（ρ=0.399）呈显著正相关（p 值均≤0.017）。IL6 与厚壁菌门（ρ=-0.398）和 TM7（ρ=-0.423）呈显著负相关，TNFα 与厚壁菌门（ρ=-0.344）也呈显著负相关。在类分类群中也观察到类似的发现。这些数据首次表明，血清微生物组的丰富度和组成在年轻和老年人之间存在差异，并且这些因素与与年龄相关的炎症指标有关。
