Table_2_Selective Bacterial Colonization of the Murine Larynx in a Gnotobiotic Model.XLSX

The larynx is a mucosal organ situated between the respiratory and gastrointestinal tracts. Little is known about microbial contributions to laryngeal epithelial health and pathogenesis. Developing a gnotobiotic laryngeal model will introduce new avenues for targeted explorations of microbes in laryngeal mucosal biology, allowing for enhanced understanding of host–microbe interaction in the upper airway. In this study, we first assessed the potential of using gut microbiota as a source to establish laryngeal microbiota in germ-free mice. Results demonstrated the selective nature of the upper airway and provided evidence that gut bacteria can assemble into communities that resemble the commensal resident bacteria occurring in the larynx of conventionally-raised animals phylogenetically and functionally. Then, we confirmed the reproducibility of laryngeal colonization through comparison of laryngeal microbiota in the larynx along with neighboring regions (base of tongue, esophagus, and trachea) between conventionally-raised and germ-free mice that conventionalized with cecal microbiota. Despite taxonomic differences, the established laryngeal microbiota from cecal content exhibited similarity to commensal resident microbiota in diversity within/between communities and predicted metagenomic functions. Our data also suggests little difference in bacterial distribution across the larynx and its surrounding regions and that cell motility and the ability to degrade xenobiotics is critical for bacteria colonizing upper airway. Successful colonization of laryngeal and oropharyngeal regions with gut microbiota in our study will greatly facilitate the investigation of potential localized inflammatory responses within host tissues that contribute to the disorders of essential laryngeal functions. Utilizing said gnotobiotic model to conduct future studies will allow for novel insights into direct microbial contributions to laryngeal epithelial health and pathogenesis.

喉（larynx）是一种坐落于呼吸道与消化道之间的黏膜器官。目前学界对微生物在喉上皮健康与疾病发病机制中的作用仍知之甚少。构建悉生（gnotobiotic）喉黏膜模型，将为靶向探究喉黏膜生物学中的微生物提供全新研究路径，有助于深化对上呼吸道宿主-微生物互作机制的认知。本研究首先评估了以肠道菌群为来源，在无菌（germ-free）小鼠体内构建喉菌群的可行性。研究结果证实了上呼吸道的选择性定植特性，并提供证据表明：肠道细菌可形成在系统发育与功能层面，均与常规饲养动物喉腔内共生常驻菌群相似的群落结构。随后，本研究通过对比常规饲养小鼠与经盲肠菌群定植的无菌小鼠的喉腔及其邻近区域（舌根部、食管与气管）的菌群组成，验证了喉腔定植实验的可重复性。尽管菌群分类组成存在差异，但从盲肠内容物中构建的喉菌群，在群落内部与群落间的多样性以及预测宏基因组功能层面，均与共生常驻菌群具有相似性。本研究数据还显示，喉腔及其周边区域的细菌分布差异极小；且细菌的运动能力与降解外源性物质（xenobiotics）的能力，对于其在上呼吸道定植至关重要。本研究中肠道菌群在喉腔与口咽区域的成功定植，将极大推动针对宿主组织内潜在局部炎症反应的研究——这类炎症反应与喉核心功能紊乱密切相关。未来利用该悉生模型开展研究，将为阐明微生物直接调控喉上皮健康与发病机制的作用提供全新见解。