Molecular characterization of the ocular microbiome in healthy adults

总结 眼表经常暴露于环境中，并被几种微生物所居住。 最常用的眼表微生物组表征方法包括 传统的微生物培养和最近的下一代测序。基于培养 方法提供了绝对丰度的信息，但仅限于识别快速生长的 培养基上的微生物和大量不可培养的微生物。近期16 S rRNA 标记基因测序研究提供了最广泛和多样化的表征， 眼部微生物组该数据表明存在常驻眼部微生物组;然而， 关于健康人群中前段的核心微生物组成分知之甚少。 此外，将产生最具代表性的结果的样品收集的最佳方法 仍不清楚本研究旨在实现全宏基因组测序（WMS）， 为低生物量样品优化的元转录组学测序方法， 栖息在眼前段的眼部微生物组及其与免疫系统的相互作用 在健康的成年人中。在这个项目中，我们将建立一个大型的人类队列（n=500），并将 从健康成人的下穹窿和上级结膜穹窿前瞻性地收集系列样品 为期一年。除了表征健康成年人的核心眼部微生物组外， 将研究特定微生物分类群（细菌， 真菌和病毒）;性别和不同年龄组（年轻人）之间的眼部微生物组差异 成年人、中年人和老年人）。元转录组学的数据可以让我们 微生物途径（细菌、真菌和病毒）和宿主上皮（结膜）免疫应答， 支持微生物组和眼部免疫调节之间的关联。的成果 这项研究将有助于了解前牙区的核心微生物成分， 片段及其在免疫相互作用中的作用以维持体内平衡。

SUMMARY The ocular surface is constantly exposed to the environment and is inhabited by several microbes. The most commonly used methods for ocular surface microbiome characterization consist of traditional microbiological culturing and, more recently, next-generation sequencing. Culture-based methods provide information on absolute abundances but are limited in identifying only fast-growing microorganisms on culture media and a large number of nonculturable microbes. Recent 16S rRNA marker gene sequencing studies provide the most extensive and diverse characterization of the ocular microbiome. This data suggests the existence of the resident ocular microbiome; however, little is known about the core microbiome constituents of the anterior segment in a healthy population. Furthermore, the optimal method of sample collection that will yield the most representative results remains unclear. This study aims to implement whole-metagenome sequencing (WMS) and metatranscriptomics sequencing methods optimized for low-biomass samples to characterize the ocular microbiome inhabiting the anterior segment of the eye and their interaction with the immune system in healthy adults. In this project, we will establish a large human cohort (n=500) and will prospectively collect serial samples from inferior and superior conjunctival fornix from healthy adults for a period of 1 year. In addition to characterizing the core ocular microbiome in healthy adults, we will examine seasonal changes in the diversity and enrichment of specific microbial taxon (bacteria, fungi, and viruses); ocular microbiome differences between sexes and different age groups (young adults, middle age, and older adults). The metatranscriptomics data will enable us to profile active microbial pathways (bacteria, fungi, and virus) and host epithelial (conjunctival) immune response for underpinning associations between the microbiome and ocular immune modulation. The outcomes of this study will contribute towards understanding the core microbial constituents in the anterior segment and their role in immune interactions to maintain homeostasis.