Iron is an essential micronutrient for life. In mammals, dietary iron is absorbed primarily in the small intestine. Currently, the impacts of dietary iron on the taxonomic structure and function of the gut microbiome and reciprocal effects on the animal host are not well understood. Here, we establish a mouse model of low-iron challenge in which intestinal biomarkers and reduced fecal iron reveal iron stress while serum iron and mouse behavioral markers indicate maintenance of iron homeostasis. We show that the diversity of the gut microbiome in conventional C57BL/6 mice changes dramatically during 2 weeks on a low-iron diet. We also show the effects of a low-iron diet on microbiome diversity are long lasting and not easily recovered when iron is returned to the diet. Finally, after optimizing taxon association methods, we show that some bacteria are unable to fully recover after the low-iron challenge and appear to be extirpated from the gut entirely. In particular, operational taxonomic units (OTUs) from the Prevotellaceae and Porphyromonadaceae families and Bacteroidales order are highly sensitive to low-iron conditions, while other seemingly insensitive OTUs recover. These results provide new insights into the iron requirements of gut microbiome members and add to the growing understanding of mammalian iron cycling.

中文翻译：

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动态肠道微生物组对低铁挑战的响应变化

铁是生命中必不可少的微量营养素。在哺乳动物中，饮食中的铁主要在小肠中吸收。目前，饮食铁对肠道微生物组的分类结构和功能的影响以及对动物宿主的相互影响尚不十分清楚。在这里，我们建立了低铁挑战的小鼠模型，其中肠道生物标志物和粪便铁含量降低揭示了铁应激，而血清铁和小鼠行为标志物表明铁稳态得以维持。我们显示，常规C57BL / 6小鼠中肠道微生物组的多样性在低铁饮食的2周内发生了巨大变化。我们还表明，低铁饮食对微生物组多样性的影响是持久的，并且当铁返回饮食时不容易恢复。最后，优化分类单元关联方法后，我们表明，在低铁攻击后，某些细菌无法完全恢复，并且似乎完全从肠道中消失了。特别是来自vo前科和卟啉单胞菌科和拟杆菌属对低铁条件高度敏感，而其他看似不敏感的OTU则恢复。这些结果提供了对肠道微生物组成员铁需求的新见解，并增加了对哺乳动物铁循环的日益了解。