The Microbiome and Ocular Surface Disease
Purpose of Review
The human body lives in a symbiotic relationship with the bacteria, viruses, fungi, and protozoa that make up the microbiome. In this review, we discuss the compositions of the gut and ocular surface microbiomes in relationship to health and disease.
The gut microbiome is dominated by Firmicutes, whereas the ocular surface is dominated by Proteobacteria. The compositions of the microbiome are similar between individuals at the phyla level, but differ at the genus level. Alterations in the microbiome have been associated with disease. For example, ocular diseases such as uveitis, dry eye, and keratitis have been associated with gut dysbiosis. In addition, ocular surface dysbiosis has been reported in diseases including dry eye, blepharitis, keratitis, and diabetic retinopathy.
Compositions of the gut and ocular surface microbiomes have been found to differ in disease states compared with controls. Further understanding of dysbiosis specific to a disease is needed to target these surfaces for therapeutic strategies.
KeywordsGut microbiome Ocular surface disease Dysbiosis Gut-eye axis
This study was supported by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Clinical Sciences Research EPID-006-15S (Dr. Galor), R01EY026174 (Dr. Galor), NIH Center Core Grant P30EY014801, and Research to Prevent Blindness Unrestricted Grant.
Compliance with Ethical Standards
Conflict of Interest
Arjun Watane, Kara M. Cavuoto, Santanu Banerjee, and Anat Galor each declare no potential conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 1.Baim AD, et al., The microbiome and ophthalmic disease. Exp Biol Med (Maywood). 2018;1535370218813616.Google Scholar
- 9.• Huang Y, Yang B, Li W. Defining the normal core microbiome of conjunctival microbial communities. Clin Microbiol Infect. 2016;22(7):643 e7–643 e12. An important recent study characterizing the ocular surface microbiome, suggesting that phyla composition is consistent between individuals, but genera composition varies. CrossRefGoogle Scholar
- 27.Picchianti-Diamanti A, Panebianco C, Salemi S, Sorgi M, di Rosa R, Tropea A, et al. Analysis of gut microbiota in rheumatoid arthritis patients: disease-related dysbiosis and modifications induced by etanercept. Int J Mol Sci. 2018;19(10).Google Scholar
- 36.• Wang C, et al. Sjogren-like lacrimal keratoconjunctivitis in germ-free mice. Int J Mol Sci. 2018;19(2) This study indicates found that desiccating stress in germ-free mice resulted in a worse dry eye phenotype compared with control mice. Google Scholar
- 38.•• Kugadas A, et al. Impact of microbiota on resistance to ocular Pseudomonas aeruginosa-induced keratitis. PLoS Pathog. 2016;12(9):e1005855. An important study finding that when the gut of germ-free mice was re-colonized with human or mouse microbiomes, the mice became less susceptible to infection and had improved neutrophil function. CrossRefGoogle Scholar
- 44.• Morita Y, et al. Lactobacillus paracasei KW3110 prevents blue light-induced inflammation and degeneration in the retina. Nutrients. 2018;10(12). A study suggesting that eye disease may be able to be prevented with gut microbiome modulation through probiotics. Google Scholar
- 55.Kulaçoğlu DN, Özbek A, Uslu H, Şahin F, Güllülü G, Koçer I, Karabela Y. Comparative lid flora in anterior blepharitis. Turk J Med Sci. 2001;31:359–63.Google Scholar
- 57.•• St Leger AJ, et al. An ocular commensal protects against corneal infection by driving an interleukin-17 response from mucosal gammadelta T cells. Immunity. 2017;47(1):148–158 e5. This study shows that the depletion of C. mastitidis from the ocular surface was associated with increased susceptibility to keratitis with C. albicans and P. aeruginosa, suggesting a role of the OSM in ocular surface immunity. CrossRefGoogle Scholar