Seeing Clearly: Gut-Related Problems Affect the Eyes

With links to the gut, several eye diseases could potentially be prevented or treated by restoring microbiome homeostasis.

When Dr. Edward Kondrot first asks his patients,“What did you do this summer?”—it’s not small talk—it’s part of his exam.

An ophthalmologist and homeopathic doctor, Kondrot wants to get to know his patients’ dispositions and immediate struggles. Those who launch into grumbles and complaints are likely under stress—one of many factors that he said can affect their vision.

His “get to know you” questions continue through daily habits, work, and even digestion. How patients think and their lifestyle decisions factor into both gut and eye symptoms, which are more interconnected than most people realize, Kondrot told The Epoch Times.

Leaky Barriers

A growing number of lifestyle factors—such as diet, stress, antibiotics, drugs, and alcohol—have been associated with dysbiosis and compromised intestinal barrier function, sometimes described as “leaky gut.”

Leaky gut is a bit of a controversial notion, as our intestinal mucosa is designed to be permeable, and there’s no standardized test to gauge whether loose junctions in the intestinal epithelium are allowing harmful toxins into our bloodstream. Leaky gut can also be a moving target for lab tests, as the intestinal lining renews itself in cell turnover every two to four weeks.

But researchers have also connected intestinal permeability to dysbiosis, which is linked to compromised health in other locations within the body, the review said. One location is the ocular mucosa—the barrier that protects the eye against allergic, inflammatory, and infectious invasion. This interface is also known as the gut-eye axis.

“Loss of intestinal barrier integrity and increased vascular permeability allow bacterial translocation and their products into the bloodstream, leading to passage across the blood-retinal barrier,” according to the review.

Bacteria products are lipopolysaccharides, commonly referred to as endotoxins, that cause chronic inflammation.

Researchers don’t know the exact mechanics involved in diseases linked through the gut-eye axis, though the review noted several theories that involve an interaction between microbes and immune cells, which could cause some people to have more intestinal permeability than others.

Activated immune cells, endotoxins, and pathogenic bacteria that escape the intestine are capable of reaching the eye, where a number of inflammatory responses can take place and damage the eyes, according to the review.

This means the physiology of a number of eye diseases isn’t entirely confined to the eyes—a fact that more ophthalmologists and patients ought to take under consideration, Kondrot said.

Eye Diseases Linked to Gut

Dry eye, glaucoma, autoimmune uveitis, and retinal diseases are specific eye diseases linked to gut microbiota, according to the review.

Dry eye—A condition in which the eyes don’t make enough tears or dry too fast. Dry eye has different causes and forms—studies have noted specific increases or decreases in the number of certain bacteria that coincide with the different forms.

Glaucoma—Several studies have confirmed a link between intestinal dysbiosis and glaucoma, chronic progressive optic neuropathy, or damage to the optic nerve. Glaucoma—caused by increased eye pressure that damages the optic nerve—is the second leading cause of blindness. 

Uveitis—An infection of the middle layer of the eye called the uvea, uveitis can be caused acutely by pathogens or infections. The autoimmune form of uveitis accompanies autoimmune diseases affecting other organs. Such diseases have microbial signatures of dysbiosis.

Retinal diseases—Many different diseases, including inherited disorders, can affect the retina, which is located in the back of the eye and assists the brain in interpreting images. Dysbiosis and inflammation that lead to increased intestinal permeability and bacterial translocation play a role in retinopathies—diseases that affect central vision—which sharpens images and offers detail to our sight.

Retinal diseases include:

• Age-related macular degeneration, in which the macula that gives fine detail to sight deteriorates
• Diabetic retinopathy, which involves the swelling and leaking of fluids in the eye that can lead to retinal detachment
• Some retinal dystrophies, a group of inherited disorders that cause progressive vision loss secondary to retinal degeneration

Loss of Good Bugs

An April review concluded that an alteration of the gut microbiome leads to an elevated risk for diabetic retinopathy. Published in Microbial Pathogenesis, it said features of a gut microbiome associated with diabetic retinopathy has increased levels of harmful microbes that are potentially pathogenic and a decrease in beneficial bacteria, which help offset bad bugs by maintaining homeostasis.

The findings of the review noted that patients with diabetic retinopathy had a reduction in diversity in their microbiome, which can have more than 1,500 different microbial species. Diversity of gut bugs has been associated with better gut and overall health.

Modern practices are leading to the destruction of microbes from both topsoil and the human microbiome. That includes the heavy use of pesticides on soil and hygiene practices in response to what Kondrot described as “germaphobia.”

We kill our good bugs when we engage in habits such as the overuse of hand sanitizer and misusing antibiotics for infections that don’t require them, he said. Germaphobia can also include avoiding contact with other people, animals, and the soil—all of which can be sources of health-boosting microbes.

“Your gut is like an investment account. You want to have as many diverse investments as possible,” Kondrot said. “You really have to look at what’s happening in the gut from birth. No one in the U.S. has a healthy gut.”

Diabetes and Eyes

Dysbiosis is also linked to obesity and Type 2 diabetes, which continues to affect more Americans. As the number of people with diabetes goes up, so do the cases of diabetic retinopathy, which are expected to grow to 130 million people in 2030 and 161 million in 2045. Diabetic retinopathy occurs in about 40 percent of those whose blood sugars are not well controlled. 

Authors of the Microbial Pathogenesis review noted that gut-eye axis findings imply that re-establishing gut microbial homeostasis could prevent or treat diabetic retinopathy.

“Factors such as probiotics, glucose-lowering medications, and dietary habits have been shown to influence the gut microbiome of patients with diabetic retinopathy,” they wrote.

Probiotics are health-promoting microbes that are found in both supplements and foods such as yogurt, kimchi, kombucha, and sauerkraut.

Gut-Eye Health Tips

Kondrot offers dietary advice to patients, including eating more fermented foods that naturally contain probiotics.

“It all comes down to diet. Sugar is a poison, and sugar is changing the whole configuration of our gut. The average child’s sugar consumption, it’s a nightmare,” he said. “Food is our best medicine. You’ve got to change your diet. If it has a label on it, don’t eat it. You’ve got to get more natural food.”

Other tips Kondrot offered for better eye health:

• Reduce screen use, including television
• Play sports, which improve peripheral vision
• Avoid seed oils, which are inflammatory

In many cases, patients may explore natural healing options such as acupuncture, traditional Chinese medicine, herbal remedies, and homeopathy, he said.

Homeopathy, developed in Germany, is a form of alternative medicine that involves using highly diluted substances based on the principle that “like cures like.” For instance, a patient experiencing symptoms thought to be caused by high levels of mercury might be treated with a highly diluted form of mercurius.

Kondrot added that sometimes medicine and surgery offer the best options for patients. He performs many surgeries in impoverished areas in West Africa, where he said the lack of adequate nutrition often makes surgery the best option.

Nutrition, while more accessible in the United States, can still be complicated for patients to navigate because doctors don’t receive much training in it. Food continues to become inundated with complex ingredients and toxic practices, he said.

For instance, even salad dressing found in a health food store might have seed oil among the ingredients. Seed oils such as canola, corn, and soybean oils contain linoleic acid which can be safe in small amounts. However, when overconsumed, as in the standard American diet, seed oils have been linked to chronic disease and vision issues. Healthier alternatives are coconut, avocado, and olive oils.

Because of the bombardment of chemicals that are not only in the food supply but also in the environment, poor gut and eye health are in a “dire situation,” he said.

“That’s why we are getting sicker and sicker. We have a long way to go,” he said. “It is possible to cure disease, if you have the right approach. If we understand disease dynamics, we can really help the patients and reverse disease.”