Eye health is a fundamental component of overall well-being, yet it is often neglected until clear visual disturbances or discomfort arise. Among the various underlying causes of ocular disorders, inflammation is one of the most prevalent; if not properly managed, it can lead to significant complications.
Inflammation may be triggered by multiple factors, including infections caused by bacteria, viruses, and fungi, which can affect different parts of the eye such as the conjunctiva, cornea, and uvea, potentially leading to conditions like uveitis. Additional contributing factors include immune-mediated responses and allergies (e.g., to dust, pollen, or animal dander). Physical trauma, such as scratches or impacts, may also result in inflammatory processes.
Recent scientific evidence points to the existence of a complex biological connection between the gut microbiota and ocular health, known as the gut–eye axis. Studies increasingly highlight a strong interaction between these systems: specific gut bacteria are capable of modulating immune responses that extend to the ocular environment. In particular, intestinal dysbiosis, an imbalance between beneficial and pathogenic microorganisms, has been associated with the development of several eye conditions.
One of the most frequently studied disorders in this context is dry eye syndrome, characterized by either a reduced quantity or altered quality of the tear film, which is essential for maintaining proper lubrication and protection of the ocular surface. Emerging evidence, especially in post-COVID patients, suggests that this condition may be exacerbated by significant dysbiosis, along with a marked reduction in beneficial commensal gut bacteria, leading to a worsening of symptoms.
Ocular health is also influenced by structural and metabolic stressors, including deficiencies in key nutraceuticals and inadequate intake of essential fatty acids, both of which play a role in maintaining tissue integrity and controlling inflammation.
In addition to its connection with the gut, the eye hosts its own distinct microbiota, forming a specialized ocular ecosystem that contributes to local immune defense and homeostasis.
Among the principal inflammatory eye conditions, we find:
- Uveitis: an inflammation of the uvea, a highly vascularized structure. In addition to microbial assessment, it is important to evaluate circulatory factors. A disruption of intestinal eubiosis, accompanied by an increase in pathogenic microorganisms, may contribute to the onset and progression of significant inflammatory responses.
- Diabetic retinopathy: particularly relevant in individuals with prediabetic metabolic syndrome or diabetes mellitus. Research indicates that a low-calorie, low-glycemic-index diet can promote the growth of beneficial gut bacteria, potentially offering protective effects against the development of diabetic retinopathy.
- Keratitis: inflammation of the cornea. Studies examining the gut microbiome in patients with fungal keratitis have revealed a reduction in beneficial bacterial populations and an increase in pro-inflammatory and pathogenic strains.
Among the microorganisms currently under investigation is Corynebacterium mastitidis, a commensal bacterium residing on the ocular surface. It has been shown to stimulate immune activity and promote the production of antimicrobial molecules in tears, thereby enhancing protection against pathogenic infections.
In conclusion, evaluating the intestinal microbiota, together with preserving the physiological balance of the ocular microbiota, appears to represent a valuable strategy for both the prevention and management of ocular diseases.
For a comprehensive clinical and bioenergetic assessment of patients, the following Daphne Lab tests are recommended: Thema Intestinal Dysbiosis, Thema Immune System, and the Ocular Stress Panel.
Dr. Monica De Felice
Advanced Training Graduate and Scientific Consultant in Human and Pediatric Microbiome (University of Pavia)
S.I.B.S.
People’s University of Arezzo – Master’s Degree in Probiotic Clinical Practice and Microbiome Nutrition
International School on Microbiota in Digestive Diseases – ESNM (European Society of Neurogastroenterology and Motility)
Animal Naturopathy – AIOC Academy Italy
Cellular and System Longevity
C.T.S. Daphne Lab