How Your Gut Health Affects Your Eye Health

Woman with healthy eyes and good gut healthThe digestive tract is filled with over 100 trillion microorganisms, many of which are needed for gut health — and good health.1 The gut flora, as they are called, has a similar function to that of other organs in the body.2 The intestinal microorganisms are their own environment. This environment aids the body’s immune system and helps keep you healthy.3

The health of the eyes depends upon the health of these gut microorganisms. Age-related Macular Degeneration (AMD) and dry eye disease (DED) are impacted by inflammation in the gut.

Gut Health Basics

Seventy percent of the human immune system is a result of the complex ecosystem of microorganisms.

Dysbiosis, the interaction of these intestinal microbes, may lead to the development of various common diseases such as diabetes, neuropsychiatric diseases, and cancer. It is also a crucial factor in the risk of developing eye diseases, including uveitis, dry eye, macular degeneration, and glaucoma.

Healthy retinas are essential for vision. The retina processes light and images. That information is sent to the optic nerve. The optic nerve sends the information to the visual cortex in the brain. The brain interprets the data and tells us what we are seeing.

The retina is protected by the Blood-Retinal Barrier (BRB). The BRB isolates the eyes and removes waste products from the eyes.

Leaky Gut Syndrome

“Leaky Gut Syndrome” means that the intestines are too permeable. They allow inflammatory substances out of the gut. This process can cause damage that causes more inflammation. That inflammation can lead to more intestinal permeability. This is a vicious circle. Symptoms include bloating, cramps, gas, food sensitivities, and aches and pains.

“Leaky Gut Syndrome” can result in chronic inflammation. The body attacks these microorganisms, reacting to them like they are diseases. This can cause eye problems. Doctors often misdiagnose Leaky Gut Syndrome because it resembles many other health issues.


Research has found a clear connection between gut and eye health. This research may lead to new treatments for eye inflammation. Current treatments can cause serious side effects, including cataracts and glaucoma.

Low-grade inflammation in older adults is common. It can result from poor diet, lack of regular exercise, and other health conditions. Ongoing environmental exposures to toxins, including mold, fungus, and heavy metals, play a role in many diseases that plague seniors. Some conditions include Parkinson’s Disease, Alzheimer’s Disease, diabetes, cancer, cardiovascular disease, and these diseases of the eye:

Eye Diseases Affected by Gut Health


Uveitis is a disease that can cause blurred vision. 54 out of every 10,000 people in the USA will get this disease.4 Advancing age and smoking are risk factors. Most cases of uveitis are non-infectious. Acute anterior uveitis (AAU) represents 85% of the total cases. Recent studies have linked uveitis to poor diet and gut microorganisms.5 6

Aged-Related Macular Degeneration

Aged-Related Macular Degeneration (AMD) is one of the leading causes of vision loss. 90% of the AMD cases are Dry Macular Degeneration. Normal waste created in the eye is not completely absorbed by the body’s waste elimination system. Over time, this debris settles on the retina. The impact can be loss of retinal cells and vision loss. Wet Macular Degeneration makes up 10% of the cases. That is when the body attempts to grow new blood vessels in the eye. The new blood vessels can end up leaking. If not treated, Wet Macular Degeneration can result in rapid vision loss. The dry type may progress to become wet.

According to some research studies, macular degeneration might be essentially a form of “starvation of the retina.” Genetics may play a role. That means the essential nutrients needed to keep the retina healthy are unavailable. Other factors include poor circulation, poor diet lacking essential antioxidants, sedentary lifestyle, lack of essential microorganisms, mitochondria defects, and autoimmune disease.

AMD onset has been linked to imbalances in gut health. For example, patients with AMD had more bad microorganisms and fewer good microorganisms versus the control group.7 This enables bacterial products and pathogen-associated molecular patterns to get into the blood. As mentioned above, problems with gut microorganisms are linked with chronic inflammation and can increase intestinal permeability.

The progression of dry AMD to wet AMD is influenced by diet. Regarding diet, highly glycemic foods, obesity, oxidative stress, and a high-fat diet can worsen the severity of dry and wet AMD.8

Primary Open-Angle Glaucoma (POAG)

Glaucoma is one condition known to affect vision. Open-angle glaucoma can lead to long periods of high pressure on the eyes.9 That can cause mechanical impairment, ischemia, oxidative stress, and inflammation.

Glaucoma, if left untreated, can result in optic nerve damage. This primarily affects peripheral vision. Often referred to as the “silent thief,” glaucoma can go undetected until the person notices that they have tunnel vision. The eye doctor checks for the primary symptom of glaucoma at each visit. A tiny puff of air measures the pressure in the eye. High pressure often means glaucoma. Most cases of glaucoma are open-angle glaucoma. Over time, if left untreated, glaucoma damages the optic nerves.

A person can have glaucoma but their eye pressure is normal or low. This may be due to a lack of essential nutrients reaching the optic nerves. Hundreds of studies support a healthy diet influencing glaucoma.

POAG is linked to two variants of bacteria.10 11 Changes in the intestinal microorganisms and mitochondrial dysfunction can result in optic nerve damage.12 Researchers also identified a relationship between glaucoma and Helicobacter pylori[13 Rowan S, Taylor A.. Involvement of a gut-retina axis in protection against dietary glycemia-induced age-related macular degeneration. Proc Natl Acad Sci USA. 2018] 13 A higher rate of H. pylori infection was found in patients with glaucoma and normal tension controls.14

Dry Eye and Contact Lenses

Dry eye is a condition caused by the inability of tears to provide enough moisture to the eyes. The main symptoms are discomfort, vision problems, and potential damage to the eyes.15 The eye’s surface is a complex system that includes the cornea (which signals the brain to produce more or fewer tears), a group of glands, and the neural network. These all work together for healthy tear production. One of the other components to be considered is gut health.

The ocular surface microorganisms are similar to gut microorganisms. In a recent study, in every part of the ocular surface, microorganisms were detected. The disruption of the microorganism is a factor in patients suffering from Dry Eye Disease (DED).16 17 The disruption of the eyes’ microorganisms is evident in chronic contact lens users and DED, which can cause an immune response.

One study used probiotic eye drops on patients over 4 weeks, applied four times a day. They were applied in both eyes for one month after three days of washout,18 which relieved signs and symptoms.19 Proper care should be taken when wearing contact lenses.


When one of the eyes’ glands has a swelling or blockage, the lump that forms is called a chalazion. Factors involved in this condition can include immunological, irritable bowel syndrome, iatrogenic infections,20 21 especially related to S. aureus and Propionibacterium acnes, and demodicosis (Demodex mite infestation).22 Vitamin A deficiency and diabetes23 24 can also be factors.

Changes in the eyes’ surface microorganisms could impact eye health. Exposure to various environmental factors, including diet, toxins, antibiotics, and pathogens, can all lead to dysbiosis.


A number of studies have confirmed a relationship between gut and eye health.25 More research is underway to understand this relationship further.

Microbiome Supplements

MegaSporeBiotic 60 caps – Promotes healthy gut flora balance, and supports overall eye and body health.

MegaPre Capsules 180 ct – Prebiotic to help promote healthy gut flora without feeding potential pathogens.

Suggested Supplements

Advanced Eye & Vision Support Formula (whole food) 60 vcaps

Dr. Grossman’s Meso Plus Retinal Support and Computer Eye Strain Formula with Astaxanthin 90 vcaps

Dr. Grossman’s Advanced Eye and Dr. G’s Whole Food Superfood Multi1 20 Vcap Combo – 2 months supply

ReVision Formula (wild-crafted herbal formula) 2 oz – based on classic Chinese medicine Liver tonic formula to help support healthy circulation and blood flow throughout the eyes and body.

Dr. Grossman’s Vitamin C Plant-Based Formula – 60 caps

Dr. Grossman’s Premium Turmeric Vcaps (Organic)

Recommended Books

Natural Eye Care: Your Guide to Healthy Vision and Healing

Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia, and Other Related Diseases Naturally


  1. Thursby E, Juge N. Introduction to the human gut microbiota. Biochem J. 2017;474(11):1823–1836
  2. O’Hara AM, Shanahan F. The gut flora as a forgotten organ. EMBO Rep. 2006;7(7):688–693
  3.  Vrancken G, Gregory AC, Huys GRB, et al.. Synthetic ecology of the human gut microbiota. Nat Rev Microbiol. 2019;17(12):754–763
  4. González MM, et al.. Epidemiology of uveitis in a US population-based study. J Ophthalmic Inflamm Infect. 2018;8(1):6.
  5. Huang X, et al.. Gut microbiota composition and fecal metabolic phenotype in patients with acute anterior uveitis. Investig Ophthalmol Vis Sci. 2018;59(3):1523–1531
  6. Rosenbaum JT, Asquith M.. The microbiome and HLA-B27-associated acute anterior uveitis. Nat Rev Rheumatol. 2018;14(12):704–713
  7. Zinkernagel MS. Association of the intestinal microbiome with the development of neovascular age-related macular degeneration. Sci Rep. 2017;7:40826
  8. Rowan S, Taylor A.. Involvement of a gut-retina axis in protection against dietary glycemia-induced age-related macular degeneration. Proc Natl Acad Sci USA. 2018
  9. Tham YC, Li X, Wong TY, et al.. Global prevalence of glaucoma and projections of glaucoma burden through 2040: A systematic review and meta-analysis. Ophthalmology. 2014;121(11):2081–2090
  10. Baim AD, Movahedan A, Farooq AV, et al.. The microbiome and ophthalmic disease. Exp Biol Med. 2019;244(6):419–429
  11. Organisciak D, et al.. Light-induced retinal degeneration is prevented by zinc, a component in the age-related eye disease study formulation. Photochem Photobiol. 2012;88(6):1396–1407
  12. Lascaratos G, Garway-Heath DF, Willoughby CE, et al.. Mitochondrial dysfunction in glaucoma: Understanding genetic influences. Mitochondrion. 2012;12(2):202–212
  13. Cani PD, Possemiers S, Van de Wiele T, et al.. Changes in gut microbiota control inflammation in obese mice through a mechanism involving GLP-2-driven improvement of gut permeability. Gut. 2009;58(8):1091–1103
  14. Chan CC, Smith JA, Shen DF, et al.. Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma. Histol Histopathol. 2004;19(4):1219–1226
  15. Astafurov K, Elhawy E, Ren L, et al.. Oral microbiome link to neurodegeneration in glaucoma. PLoS One. 2014;9(9):e104416
  16. Kim JM, Kim SH, Park KH, et al.. Investigation of the association between helicobacter pylori infection and normal tension glaucoma. Investig Ophthalmol Vis Sci. 2011;52(2):665–668
  17. Kountouras J, Mylopoulos N, Konstas AGP, et al.. Increased levels of Helicobacter pylori IgG antibodies in aqueous humor of patients with primary open-angle and exfoliation glaucoma. Graefe’s Arch Clin Exp Ophthalmol. 2003;241(11):884–890
  18. Petersen C, Round JL.. Defining dysbiosis and its influence on host immunity and disease. Cell Microbiol. 2014;16(7):1024–1033
  19. Iovieno A, Lambiase A, Sacchetti M, et al.. Preliminary evidence of the efficacy of probiotic eye-drop treatment in patients with vernal keratoconjunctivitis. Graefe’s Arch Clin Exp Ophthalmol. 2008;246(3):435–441
  20. Sklar BA, Gervasio KA, Leng S, et al.. Management and outcomes of proteasome inhibitor associated chalazia and blepharitis: a case series. BMC Ophthalmol. 2019;19(1):110
  21. Nemet AY, Vinker S, Kaiserman I.. Associated morbidity of chalazia. Cornea. 2011;30(12):1376–1381
  22. Yam JCS, Tang BSF, Chan TM, et al.. Ocular demodicidosis as a risk factor of adult recurrent chalazion. Eur. J. Ophthalmol. 2013
  23. Burkhart CG, Burkhart CN.. Similar to acne vulgaris, bacteria may produce the biological glue that causes plugging of the meibomian gland leading to chalazions. Clin Exp Ophthalmol. 2008
  24. Bonifazi E. Linear chalaziosis. Eur J Pediatr Dermatol. 2005
  25. Lu LJ, Liu J.. Human microbiota and ophthalmic disease. Yale J Biol Med. 2016;89(3):325–330