Department of Biology, University of Kentucky, 101 T.H.M. Building, Lexington, KY, 40506, USA.
Department of Biology, Indiana University, Bloomington, IN, USA.
Microb Ecol. 2023 Oct;86(3):2149-2160. doi: 10.1007/s00248-023-02233-7. Epub 2023 May 3.
Identifying the major forces driving variation in gut microbiomes enhances our understanding of how and why symbioses between hosts and microbes evolved. Gut prokaryotic community variation is often closely associated with host evolutionary and ecological variables. Whether these same factors drive variation in other microbial taxa occupying the animal gut remains largely untested. Here, we present a one-to-one comparison of gut prokaryotic (16S rRNA metabarcoding) and microeukaryotic (18S rRNA metabarcoding) community patterning among 12 species of wild lemurs. Lemurs were sampled from dry forests and rainforests of southeastern Madagascar and display a range of phylogenetic and ecological niche diversity. We found that while lemur gut prokaryotic community diversity and composition vary with host taxonomy, diet, and habitat, gut microeukaryotic communities have no detectable association with any of these factors. We conclude that gut microeukaryotic community composition is largely random, while gut prokaryotic communities are conserved among host species. It is likely that a greater proportion of gut microeukaryotic communities comprise taxa with commensal, transient, and/or parasitic symbioses compared with gut prokaryotes, many of which form long-term relationships with the host and perform important biological functions. Our study highlights the importance of greater specificity in microbiome research; the gut microbiome contains many "omes" (e.g., prokaryome, eukaryome), each comprising different microbial taxa shaped by unique selective pressures.
确定驱动肠道微生物组变异的主要力量可以增强我们对宿主和微生物之间共生关系如何以及为何进化的理解。肠道原核生物群落的变异通常与宿主进化和生态变量密切相关。这些相同的因素是否会驱动占据动物肠道的其他微生物类群的变异在很大程度上尚未得到检验。在这里，我们对来自马达加斯加东南部干旱森林和雨林的 12 种野生狐猴的肠道原核生物（16S rRNA 代谢组学）和微真核生物（18S rRNA 代谢组学）群落模式进行了一对一的比较。狐猴表现出一系列的系统发育和生态位多样性。我们发现，虽然狐猴肠道原核生物群落的多样性和组成随宿主分类学、饮食和栖息地而变化，但肠道真核生物群落与这些因素均无明显关联。我们得出的结论是，肠道真核生物群落的组成在很大程度上是随机的，而肠道原核生物群落在宿主物种之间是保守的。与肠道原核生物相比，肠道真核生物群落可能有更大比例的类群包含共生、暂时和/或寄生共生的类群，其中许多类群与宿主形成长期关系并发挥重要的生物学功能。我们的研究强调了在微生物组研究中需要更大的特异性；肠道微生物组包含许多“组”（例如原核组、真核组），每个组都由独特的选择压力塑造的不同微生物类群组成。
