Esophageal microbiota during homeostasis, dysbiosis and following microbiota transplantation. Mouse Microbiome

The esophagus is colonized with bacteria but their interactions with the host esophageal epithelium remain unknown. Here, we describe the basic properties of the esophageal microbiome in mice. We report that the esophagus of specific pathogen free (SPF) mice is colonized with diverse and unique microbial communities within the first month of life. The esophageal microbiota is distinct from other anatomical sites examined, dominated by Firmicutes, and demonstrates spatial heterogeneity as the distal esophagus is enriched in Lactobacilli and has less Streptococci compared with the proximal esophagus. Microbiota transplantation restores the residential esophageal microbiota of germ-free mice, including the spatial heterogeneity, demonstrating that the local environment drives diversity. In addition, microbiota colonization modifies esophageal gene expression and is enriched in pathways associated with epithelial barrier function. Systemic antibiotic exposure reduces the abundance of Firmicutes, expands Actinobacteria and Tenericutes and exaggerates type 2 allergic inflammation in the esophagus. Taken together, these data establish the composition, transplantation potential, antibiotic responsiveness, and host-microbiota interaction in the esophagus, and have implications for both health and disease.

食管定植有细菌，但目前学界对其与宿主食管上皮的相互作用仍不甚明晰。本研究系统阐述了小鼠食管微生物组的基本特性：研究发现，无特定病原体（Specific Pathogen Free, SPF）小鼠的食管在出生后首个月内即定植有多样且独特的微生物群落；该菌群与其他检测过的解剖部位菌群存在显著差异，以厚壁菌门（Firmicutes）为优势菌门，并呈现空间异质性——相较于食管近端，食管远端富集乳杆菌属（Lactobacilli），而链球菌属（Streptococci）丰度更低。微生物组移植可重建无菌小鼠的原位食管微生物组，包括其空间异质性，这表明局部微环境主导了菌群多样性的形成。此外，微生物组定植可改变食管的基因表达谱，并富集与上皮屏障功能相关的通路。全身抗生素暴露会降低厚壁菌门的丰度，扩张放线菌门（Actinobacteria）和柔壁菌门（Tenericutes）的占比，并加剧食管内的2型变应性炎症。综上，本研究明确了食管微生物组的组成、移植可行性、对抗生素的响应特征以及宿主-微生物组互作关系，其研究结果对食管健康与疾病的相关研究均具有重要参考价值。