The influence of the gut microbiome on eye health

Mila Ioussifova, OD, CNS, FAAO, FOWNS, discussed the gut–eye axis, emphasizing the pivotal role of the gut microbiome—and particularly gut dysbiosis—in a wide spectrum of ocular diseases. She noted that disturbances in the gut microbiota can influence conditions such as dry eye disease, uveitis, diabetic retinopathy, age-related macular degeneration, and glaucoma. Because dry eye is an immune-mediated condition, Ioussifova urged clinicians to think beyond the ocular surface. If conventional surface-directed therapies fail, underlying systemic inflammation—often originating in the gut—should be considered.

Ioussifova explained that a large proportion of the body’s immune cells reside in the gut, and that an imbalance between pathogenic and commensal (beneficial) bacteria can drive inflammatory processes both locally and systemically, ultimately affecting the ocular surface. She broadens the clinical history to include birth history (C-section vs. vaginal delivery), breastfeeding, antibiotic exposure, stress, diet, sleep, and exercise, all of which shape the gut microbiome over time. Her therapeutic approach often centers on personalized nutritional recommendations aimed at “healing the gut” as a pathway to improving not only eye health but overall wellbeing.

On probiotics, Ioussifova stressed that benefits are strain-specific, and that probiotics alone are insufficient without adequate prebiotic support. Prebiotics—primarily fiber and phytonutrient-rich, colorful, diverse plant foods—provide essential substrate for beneficial microbes to thrive. She highlights a comprehensive lifestyle focus, including stress management, physical activity, and quality sleep, as integral to microbiome health.

Ioussifova noted that evidence linking the gut microbiome to noncommunicable diseases is robust outside eye care, and ophthalmic research in this area is rapidly emerging, with disease-specific microbial patterns beginning to be recognized. She sees optometrists as uniquely positioned to address nutrition given their time with patients and existing discussions on omega-3 fatty acids and carotenoids. She encourages adding structured nutritional and lifestyle counseling, supported by handouts and validated tools.

Finally, Ioussifova recommended resources such as the Ocular Wellness and Nutrition Society for evidence-based education, and Scope Connect for assessment questionnaires and practical guidance on dietary intake and “healthy for your eyes” recommendations, helping clinicians integrate nutrition and wellness more confidently into eye care.