Analysis of Conjunctival Sac Microbiome in Dry Eye Patients With and Without Sjögren's Syndrome

Abstract

PurposeTo analyze the conjunctival sac microbial communities in patients with Sjögren's syndrome-associated dry eyes (SSDE) and non-Sjögren's syndrome-associated dry eyes (NSSDE), compared with normal controls (NC).MethodsConjunctival sac swab samples from 23 eyes of SSDE, 36 eyes of NSSDE, and 39 eyes of NC were collected. The V3–V4 region of the 16S ribosomal RNA (rRNA) gene high-throughput sequencing was performed on an Illumina MiSeq platform and analyzed using Quantitative Insights Into Microbial Ecology (QIIME). Alpha diversity was employed to analyze microbiome diversity through Chao1 and Shannon indexes. Beta diversity was demonstrated by the principal coordinates analysis (PCoA) and Partial Least Squares Discrimination Analysis (PLS-DA). The relative abundance was bioinformatically analyzed at the phylum and genus levels.ResultsThe alpha diversity was lower in patients with dry eye disease (Shannon index: NC vs. SSDE: P = 0.020, NC vs. NSSDE: P = 0.029). The beta diversity showed divergent microbiome composition in different groups (NC vs. SSDE: P = 0.001, NC vs. NSSDE: P = 0.001, NSSDE vs. SSDE: P = 0.005). The top 5 abundant phyla were Firmicutes, Proteobacteria, Actinobacteriota, Bacteroidota, and Cyanobacteria in all three groups. The top five abundant genera included Acinetobacter, Staphylococcus, Bacillus, Corynebacterium, and Clostridium_sensu_stricto_1. The relative microbiome abundance was different between groups. The Firmicutes/Bacteroidetes (F/B) ratio was 6.42, 7.31, and 9.71 in the NC, NSSDE, and SSDE groups, respectively (NC vs. SSDE: P = 0.038, NC vs. NSSDE: P = 0.991, SSDE vs. NSSDE: P = 0.048).ConclusionThe diversity of conjunctival sac microbiome in patients with NSSDE and SSDE was diminished compared with NC. The main microbiome at the phylum and genus level were similar between groups, but the relative abundance had variations. The Firmicutes/Bacteroidetes ratio was higher in the SSDE group.

Microbiome and immune-mediated dry eye: a review

“…Unlike the Texas study, individuals with Sjögren’s had a significantly decreased alpha diversity compared with controls and NDE, as well as significant compositional differences (beta diversity) between the three groups. Most pronounced differences included a significantly increased relative abundance of Actinobacteria in the SDE group compared with both the NDE group and controls and a significantly decreased Cyanobacteria and Bacteroides abundance in the SDE group compared with controls 59. Similarly, in a South Korean study that examined the OSM in 48 individuals with primary Sjögren’s compared with 72 subjects with NDE, a significantly reduced alpha diversity was noted in the Sjögren’s group compared with NDE.…”

“…Most pronounced differences included a significantly increased relative abundance of Actinobacteria in the SDE group compared with both the NDE group and controls and a significantly decreased Cyanobacteria and Bacteroides abundance in the SDE group compared with controls. 59 Similarly, in a South Korean study that examined the OSM in 48 individuals with primary Sjögren’s compared with 72 subjects with NDE, a significantly reduced alpha diversity was noted in the Sjögren’s group compared with NDE. On the other hand, significant compositional differences were not identified between the groups.…”

Altered Lung Microbiome and Metabolome Profile in Children With Pulmonary Arterial Hypertension Associated With Congenital Heart Disease

“…We assumed that there were individual differences among recruited participants and further studies with large cohorts size are needed to provide more evidence of global differences of lung microbes with PCoA clustering. PLS-DA, as the supervised method, could achieve clustering for different groups but with full awareness of the group labels ( 52 – 54 ). Composition analysis showed that there were bacterial disturbances in some taxa, despite the most common phyla and genera reported previously ( 39 , 50 ) being the same among the three groups.…”

Role of the ocular surface microbiome in allergic eye diseases

“…In Demodex blepharitis, the relative abundance of Proteobacteria has been shown to be higher, with lower abundances of Actinobacteria and Firmicutes in the patients with blepharitis compared to healthy controls [19]. Lower microbiome diversity was also seen in patients with non-Sjogren-associated dry eye compared to normal controls [20]. In addition, systemic diseases such as diabetes may also impact the composition of the OSM [21].…”