Targeting the Gut–Eye Axis: An Emerging Strategy to Face Ocular Diseases

Abstract

The human microbiota refers to a large variety of microorganisms (bacteria, viruses, and fungi) that live in different human body sites, including the gut, oral cavity, skin, and eyes. In particular, the presence of an ocular surface microbiota with a crucial role in maintaining ocular surface homeostasis by preventing colonization from pathogen species has been recently demonstrated. Moreover, recent studies underline a potential association between gut microbiota (GM) and ocular health. In this respect, some evidence supports the existence of a gut–eye axis involved in the pathogenesis of several ocular diseases, including age-related macular degeneration, uveitis, diabetic retinopathy, dry eye, and glaucoma. Therefore, understanding the link between the GM and these ocular disorders might be useful for the development of new therapeutic approaches, such as probiotics, prebiotics, symbiotics, or faecal microbiota transplantation through which the GM could be modulated, thus allowing better management of these diseases.

Consumption of Limosilactobacillus fermentum Inhibits Corneal Damage and Inflammation in Dry Eye Disease Mouse Model through Regulating the Gut Microbiome

“…Sci. 2024, 25, x FOR PEER REVIEW 10 of 17 chemokines [26]. In the present study, the p-JNK/JNK ratio and IL-1β protein level were significantly increased in the conjunctiva of the DE group relative to the CON group, as measured by Western blotting.…”

“…In the atropine model, DE is induced by the administration of 1% atropine sulfate to the ocular surface three times daily for 5 days. Mouse models of Sj chemokines [26]. In the present study, the p-JNK/JNK ratio and IL-1β protein level were significantly increased in the conjunctiva of the DE group relative to the CON group, as measured by Western blotting.…”

“…Inflammation contributes significantly to chronic ocular surface damage, and can impair tear film homeostasis, perpetuating a vicious cycle [ 44 , 45 ]. Destruction of the eye barrier by corneal dryness induces an inflammatory response to external pathogens and increases the production of inflammatory cytokines, including TNF, IL-6, IL-8, and chemokines [ 26 ]. In the present study, the p-JNK/JNK ratio and IL-1β protein level were significantly increased in the conjunctiva of the DE group relative to the CON group, as measured by Western blotting.…”

“…Recent studies have reported an association between ocular diseases and the microbiota profile of the host intestine. This is called the ‘gut–eye axis’, which indicates that changes in the gut microbiome alter host immunity, with a consequential influence on ocular health and disease [ 25 , 26 ]. Furthermore, the gut microbiome is associated with a myriad of pathophysiological processes in the host, especially chronic inflammatory diseases [ 27 , 28 , 29 , 30 ].…”

Longitudinal Changes of Ocular Surface Microbiome in Patients Undergoing Hemopoietic Stem Cell Transplant (HSCT)

“…Dry eye disease (DED) is the hallmark of ocular chronic GVHD (oGVHD) and is used for its diagnosis, scoring, and prognosis assessment [ 13 , 14 , 15 ]. There is no evidence so far of a link between the gut microbiome and ocular surface microbiome, although a gut–eye axis has been hypothesized and the role of gut microbiota on ocular disease onset has been extensively analyzed [ 16 ].…”