How stable is the microbiome of the human ocular surface?

Abstract

Purpose : The ocular surface is not a sterile place but is colonized by microbes including bacteria, viruses and fungi. These microbes and their genetic material were defined as ocular surface microbiome (OSM). The OSM may play a key role in health and disease of the ocular surface, such as dry eye disease. Although modern sequencing methods allow a more thorough characterization of the OSM compared to traditional cultivation techniques, the variability and stability of the OSM in healthy subjects have rarely been studied so far. This description, however, may contribute to the definition of a “core microbiome”. This study uses whole-metagenome shotgun sequencing to assess the stability and variation in composition and function of the OSM in the healthy human ocular surface over time.

Methods : This is a longitudinal study including 27 individuals (aged 40-60 years, 17 females and 10 males), without ocular surface disease. Samples were collected at three time points (baseline, after 2 and 8 months). For microbial DNA isolation and host depletion, we used the QIAamp Microbiome Kit (Qiagen). Whole-metagenome shotgun sequencing was performed by the Next Generation Sequencing Platform of the University of Bern, Switzerland. We used the Multivariable Association with Linear Models (MaAsLin 2) R package for data analysis.

Results : The results of this study will be presented at the ARVO 2023.

Conclusions : The study provides more detailed knowledge about the stability and variation of the healthy OSM and therefore may contribute to the definition of a “core microbiome” of the ocular surface. The results offer the basis for further studies on the role of the OSM in health and disease and the development of new strategies for the prevention and microbiome-targeting treatment of ocular diseases.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.