Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Department of Biology, Elmhurst University, Elmhurst, IL 60126, USA.
FEMS Microbiol Ecol. 2021 Mar 8;97(3). doi: 10.1093/femsec/fiab021.
Understanding the forces that shape vertebrate gut microbial community assembly and composition throughout development is a major focus of the microbiome field. Here, we utilize the complex life cycle of the eastern newt (Notophthalmus viridescens) as a natural wild model to compare the effects of host and environmental factors on gut microbiome development. We compared bacterial inventories of each of the newt's three physiologically distinct developmental stages to determine if each hosted a unique community, or if the two stages which share an aquatic habitat (larvae and adults) harbored more similar communities than those of the third stage, the terrestrial juvenile eft. Additionally, we assessed how the contribution of selective processes to gut microbial assembly changed through development. We found that structurally, each life stage harbored a distinct community, which may be attributable to host factors. Further, across development, we found that community assembly processes shifted from a predominance of neutral to selective forces. However, habitat may also be important in determining community membership and diversity due the uniqueness of eft communities based on these metrics. Our results are similar to those in other vertebrate taxa, suggesting that gut microbiota assembly processes may be conserved across diverse lineages.
理解塑造脊椎动物肠道微生物群落组装和组成的力量是微生物组领域的一个主要焦点。在这里，我们利用东方蝾螈（Notophthalmus viridescens）复杂的生命周期作为天然野生模型，比较宿主和环境因素对肠道微生物组发育的影响。我们比较了蝾螈的三个生理上不同发育阶段的细菌目录，以确定每个阶段是否拥有独特的群落，或者共享水生栖息地（幼虫和成虫）的两个阶段是否比第三个阶段即陆生幼体蝾螈拥有更相似的群落。此外，我们评估了选择过程对肠道微生物组装的贡献如何随着发育而变化。我们发现，从结构上看，每个生命阶段都存在独特的群落，这可能归因于宿主因素。此外，在整个发育过程中，我们发现群落组装过程从以中性为主转变为以选择为主。然而，由于基于这些指标的蝾螈群落的独特性，栖息地也可能对确定群落成员和多样性很重要。我们的结果与其他脊椎动物类群相似，表明肠道微生物群落组装过程可能在不同的谱系中是保守的。
