The initial intestinal microbiota acquired from different sources has profound impacts on animal health and productivity. In modern poultry production practices, the source(s) of the establishing microbes and their overall contribution during development of gastrointestinal tract communities are still unclear. Using fertilized eggs from two independent sources, we assessed the impact of eggshell- and environmental-associated microbial communities on the successional processes and bacterial community structure throughout the intestinal tract of chickens for up to 6 weeks post-hatch. Culturing and sequencing techniques identified a viable, highly diverse population of anaerobic bacteria on the eggshell. The jejunal, ileal, and cecal microbial communities for the egg-only, environment-only, and conventionally raised birds generally displayed similar successional patterns characterized by increasing community richness and evenness over time, with strains of Enterococcus, Romboutsia, and unclassified Lachnospiraceae abundant for all three input groups in both trials. Bacterial community structures differed significantly based on trial and microbiota input with the exception of the egg-exposed and conventional birds in the jejunum at week 1 and the ileum at week 6. Cecal community structures were different based on trial and microbiota input source, and cecal short-chain fatty acid profiles at week 6 highlighted functional differences as well. We identified distinct intestinal microbial communities and differing cecal short-chain fatty acid profiles between birds exposed to the microbiota associated with either the eggshell or environment, and those of conventionally hatched birds. Our data suggest the eggshell plays an appreciable role in the development of the chicken intestinal microbiota, especially in the jejunum and ileum where the community structure of the eggshell-only birds was similar to the structure of conventionally hatched birds. Our data identify a complex interplay between the eggshell and environmental microbiota during establishment and succession within the chicken gut. Further studies should explore the ability of eggshell- and environment-derived microbes to shape the dynamics of succession and how these communities can be targeted through interventions to promote gut health and mitigate food-borne pathogen colonization in poultry.

中文翻译：

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蛋壳和环境细菌有助于生长鸡的肠道微生物群。

从不同来源获得的初始肠道微生物群对动物健康和生产力具有深远影响。在现代家禽生产实践中，微生物的来源及其在胃肠道群落发育过程中的总体贡献仍不清楚。使用来自两个独立来源的受精卵，我们评估了蛋壳和环境相关微生物群落对鸡整个肠道的演替过程和细菌群落结构的影响，持续时间长达 6 周。培养和测序技术在蛋壳上确定了一个可行的、高度多样化的厌氧菌群。仅鸡蛋、仅环境的空肠、回肠和盲肠微生物群落，和传统饲养的鸟类通常表现出相似的演替模式，其特征是随着时间的推移增加群落的丰富度和均匀度，在两个试验中，所有三个输入组的肠球菌属、Romboutsia 和未分类的毛螺菌属菌株都很丰富。细菌群落结构因试验和微生物群输入而有显着差异，除了第 1 周的空肠和第 6 周的回肠中的鸡蛋暴露和常规鸟类。盲肠群落结构因试验和微生物群输入源而异，而盲肠第 6 周的短链脂肪酸谱也突出了功能差异。我们确定了暴露于与蛋壳或环境相关的微生物群的鸟类与传统孵化的鸟类之间不同的肠道微生物群落和不同的盲肠短链脂肪酸谱。我们的数据表明，蛋壳在鸡肠道微生物群的发育中发挥着重要作用，特别是在空肠和回肠，只有蛋壳的鸟类的群落结构与传统孵化鸟类的结构相似。我们的数据确定了在鸡肠道内建立和演替过程中蛋壳和环境微生物群之间的复杂相互作用。