ABSTRACT

The age-associated alterations in microbiomes vary across populations due to the influence of genetics and lifestyles. To the best of our knowledge, the microbial changes associated with aging have not yet been investigated in Singapore adults. We conducted shotgun metagenomic sequencing of fecal and saliva samples, as well as fecal metabolomics to characterize the gut and oral microbial communities of 62 healthy adult male Singaporeans, including 32 young subjects (age, 23.1 ± 1.4 years) and 30 elderly subjects (age, 69.0 ± 3.5 years). We identified 8 gut and 13 oral species that were differentially abundant in elderly compared to young subjects. By combining the gut and oral microbiomes, 25 age-associated oral-gut species connections were identified. Moreover, oral bacteria Acidaminococcus intestine and Flavonifractor plautii were less prevalent/abundant in elderly gut samples than in young gut samples, whereas Collinsella aerofaciens and Roseburia hominis showed the opposite trends. These results indicate the varied gut-oral communications with aging. Subsequently, we expanded the association studies on microbiome, metabolome and host phenotypic parameters. In particular, Eubacterium eligens increased in elderly compared to young subjects, and was positively correlated with triglycerides, which implies that the potential role of E. eligens in lipid metabolism is altered during the aging process. Our results demonstrated aging-associated changes in the gut and oral microbiomes, as well as the connections between metabolites and host-microbe interactions, thereby deepening the understanding of alterations in the human microbiome during the aging process in a Singapore population.

 抽象的

由于遗传和生活方式的影响，不同人群的微生物组与年龄相关的变化有所不同。据我们所知，尚未在新加坡成年人中研究与衰老相关的微生物变化。我们对粪便和唾液样本进行鸟枪法宏基因组测序，以及粪便代谢组学，以表征 62 名健康成年男性新加坡人的肠道和口腔微生物群落，其中包括 32 名年轻受试者（年龄，23.1 ± 1.4 岁）和 30 名老年受试者（年龄， 69.0 ± 3.5 年）。我们确定了 8 种肠道物种和 13 种口腔物种，这些物种在老年人和年轻受试者中的丰度存在差异。通过结合肠道和口腔微生物群，确定了 25 个与年龄相关的口腔-肠道物种联系。此外，口腔细菌肠道酸性球菌和普氏黄酮在老年肠道样本中的普遍性/丰富度低于年轻肠道样本，而产气柯林斯菌和人罗斯伯利亚则表现出相反的趋势。这些结果表明肠道-口腔通讯随着衰老而变化。随后，我们扩大了微生物组、代谢组和宿主表型参数的关联研究。特别是，与年轻受试者相比，老年人中的E.eligens数量有所增加，并且与甘油三酯呈正相关，这意味着E.eligens在脂质代谢中的潜在作用在衰老过程中发生了改变。我们的结果证明了肠道和口腔微生物组与衰老相关的变化，以及代谢物和宿主微生物相互作用之间的联系，从而加深了对新加坡人口衰老过程中人类微生物组变化的理解。