Tear film microbiome in Sjogren's and non-Sjogren's aqueous deficiency dry eyeOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined the bacterial tear film microbiome in aqueous-deficient dry eye, comparing Sjogren's syndrome (SS) and non-Sjogren's syndrome (NSS) dry eye to healthy eyes. Researchers sequenced the V3-V4 region of the 16S rRNA gene from tear film DNA samples using the Illumina HiSeq2500 platform. Taxa were assigned using the QIIME pipeline, and alpha and beta diversity were assessed statistically in R. Differences between groups were further characterized using principal coordinate analysis (PCoA), differential abundance testing, and network analysis.
Who was studied?
The study included tear film samples from 33 healthy individuals, 17 individuals with Sjogren's syndrome dry eye, and 28 individuals with non-Sjogren's syndrome dry eye, for a total of 78 participants. The abstract does not provide further demographic details such as age, sex, or geographic location of the cohorts.
What were the most important findings?
The phyla Actinobacteria, Firmicutes, and Bacteroidetes showed significant changes in both SS and NSS dry eye compared to healthy eyes, while Lactobacillus and Bacillus were the predominant genera across all three groups. PCoA and heat map analyses revealed that SS and NSS samples formed distinct clusters separate from the healthy cohort. Several genera, including Prevotella, Coriobacteriaceae UCG-003, Enterococcus, Streptomyces, Rhodobacter, Ezakiella, and Microbacterium, were significantly increased in the disease groups relative to healthy eyes.
What are the greatest implications of this study?
These findings suggest that aqueous-deficient dry eye, whether associated with Sjogren's syndrome or not, is accompanied by a distinct shift in the ocular surface microbiome rather than a uniform or random change. The clear separation between disease and healthy clusters indicates the tear microbiome could potentially serve as a biomarker to help distinguish dry eye subtypes. This work supports further investigation into whether these microbial shifts contribute to, or result from, the inflammatory processes seen in aqueous-deficient dry eye.