Resident microbes (microbiota) can shape host organismal function and adaptation in the face of environmental change. Invasion of new habitats exposes hosts to novel selection pressures, but little is known about the impact on microbiota and the host–microbiome relationship (e.g., how rapidly new microbial associations are formed, whether microbes influence invasion success). We used high‐throughput 16S rRNA sequencing of New Zealand (native) and European (invasive) populations of the freshwater snail Potamopyrgus antipodarum and found that while invaders do carry over some core microbial taxa from New Zealand, their microbial community is largely distinct. This finding highlights that invasions can result in the formation of novel host–microbiome relationships. We further show that the native microbiome is composed of fewer core microbes than the microbiome of invasive snails, suggesting that the microbiota is streamlined to a narrower set of core members. Furthermore, native snails exhibit relatively low alpha diversity but high inter‐individual variation, whereas invasive snails have higher alpha diversity but are relatively similar to each other. Together, our findings demonstrate that microbiota comparisons across native and invasive populations can reveal the impact of a long coevolutionary history and specialization of microbes in the native host range, as well as new associations occurring after invasion. We lay essential groundwork for understanding how microbial relationships affect invasion success and how microbes may be utilized in the control of invasive hosts.

中文翻译：

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入侵的淡水蜗牛形成新的微生物关系

常驻微生物（微生物群）可以塑造宿主的有机体功能和面对环境变化的适应。新栖息地的入侵使宿主面临新的选择压力，但对微生物群和宿主-微生物组关系的影响知之甚少（例如，新微生物群落形成的速度有多快，微生物是否影响入侵成功）。我们对新西兰（本土）和欧洲（入侵）淡水蜗牛Potamopyrgus antipodarum种群进行了高通量 16S rRNA 测序，发现虽然入侵者确实携带了新西兰的一些核心微生物类群，但它们的微生物群落在很大程度上是不同的。这一发现强调，入侵可能导致新的宿主-微生物组关系的形成。我们进一步表明，与入侵蜗牛的微生物组相比，天然微生物组由更少的核心微生物组成，这表明微生物组被简化为更窄的核心成员组。此外，本地蜗牛表现出相对较低的α多样性，但个体间差异较高，而入侵蜗牛具有较高的α多样性，但彼此相对相似。总之，我们的研究结果表明，本地和入侵种群之间的微生物群比较可以揭示本地宿主范围内微生物的长期共同进化历史和专业化的影响，以及入侵后发生的新关联。我们为了解微生物关系如何影响入侵成功以及如何利用微生物控制入侵宿主奠定了重要的基础。