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A Gut Feeling: How Our Gut Health Impacts Our Eyes

Posted on June 30th, 2022

Promising new studies show a link between gut health and eye health

We’ve already explored how our eyes can serve as a window into our overall health, and it turns out our gut can do the same. In recent years, research has shown the connection between the bacteria we colonize in our bodies, and our overall well being— including eye health.  

Given that the human gut comprises 70% of the immune system, our gut health can determine our susceptibility to various conditions, from mental illnesses to Age-related Macular Degeneration (AMD).  

A recent study reveals that a gut imbalance can, indeed, contribute to the progression of a number of ocular diseases, such as dry eye, glaucoma, macular degeneration and uveitis. Fortunately, there are simple ways to combat these conditions by bolstering our gut—which will also improve your overall health. It’s a win-win. 

The human gut microbiota  

Before we delve into how gut health can impact eye health, it’s important to first understand what the human gut microbiota is.  

Simply put, our bodies are filled with trillions of microbes—otherwise known as bacteria. While many of these microorganisms are actually helpful to our bodies, some can wreak havoc and cause inflammation.  

The largest population of microbes (a.k.a. bacteria) in our bodies lives inside the gut. The gut microbiota—which is sometimes referred to as the microflora of the gut—is composed of millions of genes, and strongly contributes to a person’s ability to digest food, fight disease, and even cope with stress. In short, an imbalance of unhealthy and healthy microbes in your gut is associated with a multitude of health concerns, including eye conditions.  

The health of our gut is determined by a number of factors, including the medication we take and the food we consume. Everything we put in our bodies can impact the flora in our gut, which is why prioritizing a nutritious diet is especially important for maintaining optimal gut health. Stress levels can also influence the strength of our gut, so it’s important (for more reasons than one) to manage mental health.  

How gut health impacts eye health  

Several studies have shown the role the gut microbiome plays in impacting inflammation in the body. Inflammation can lead to and exacerbate various eye conditions, including Age-related Macular Degeneration (AMD) and dry eye disease, among other ocular issues. In conjunction with inflammation concerns, studies have similarly proven that consuming an excessive quantity of foods that are high on the glycemic index can contribute to retinal problems.  

Scientists have long studied the gut-brain axis, which refers to the connection between the gut and brain. Although it’s not as widely examined, scientists are starting to believe in the existence of a gut-eye axis, which contends that the human gut is closely connected to the eyes. 

Since microbiota imbalances spur inflammation in the body, it’s believed that an unbalanced gut can propagate eye diseases, including the following:  

- Uveitis, which is inflammation of the eyes, has been widely linked to bacteria in the gut. Though the connection is still being studied, some research has shown that bacteria in the gut may prod immune cells to wrongfully attack various parts of the body, including the eyes, through auto-immune disease. 

- As is the case with uveitis, glaucoma is also linked to inflammation, as it can cause elevated intraocular pressure. An unhealthy gut and inflammation go hand in hand.  

- Macular degeneration may possibly be triggered by a disproportionate amount of firmicutes (a type of bacteria) in the gut, which causes an increase in inflammatory cytokines (proteins that are important for controlling the immune system cells). This imbalance can contribute to macular degeneration. 

- Dry eye disease, a common condition, has been linked to microbiota imbalances in recent studies. 

- Chalazion, a red bump on the eyelid (sometimes called a cyst or a meibomian cyst), is associated with consumption of too much saturated fat. Research has demonstrated a positive correlation between taking probiotic supplements, and chalazion prevention—emphasizing the link between our gut and eye health. 

While scientific exploration of the gut-eye axis is still in very early stages, there are a number of working theories that suggest a clear connection. As such, focusing on maintaining a balanced gut could also indirectly contribute to ocular health. Simply put, there’s no harm in paying more attention to your gut health. 

How to treat your gut right—and possibly prevent eye disease in the process 

There are many therapeutic approaches to bolstering your gut microbiota, which in turn, will boost your overall health and potentially prevent and treat eye diseases, too. As more is learned about the gut-eye axis, it’s likely that additional gut-targeting treatments will also come about in the near future. 

For now, though, if you wish to improve your gut health (and why wouldn’t you?!), here are some simple things you can and should do: 

- Diet  

The best way to balance your gut is to eat lots of fiber-filled and probiotic-packed foods. Fiber-rich foods, such as beans, berries, whole grains and leafy greens, will stimulate the growth of good bacteria in the gut. 

Probiotic-rich foods, particularly of the fermented variety, will do likewise. Yogurt, kimchi, and sauerkraut possess probiotic properties, which will soothe your gastrointestinal tract and reduce inflammation.  

Focusing your diet on anti-inflammatory foods, many of which we outlined in a recent article about eating with your eye health in mind, will not only support your gut, but it will likely also curb inflammation throughout the body. 

- Exercise  

Believe it or not, regularly moving your body will bolster your microbiome. Working out can actually promote a balanced gut, and some studies have found that exercise can alter the gut bacteria diversity, composition and functionality.  

Research has demonstrated that high-intensity aerobic training, and longer workouts in general, make the most dramatic difference in gut health.  

- Manage mental health  

As we mentioned, stress levels can have a direct impact on gut health. In fact, experts sometimes refer to the gut as the “second brain.” Finding ways to support your mental health—be it through therapy, journalling or deep breathing—may alleviate gut-related issues and inflammation.  

- Take a probiotic  

Probiotic supplements are widely available and there are a variety of unique formulas that target different concerns. Generally, the supplements are made up of good bacteria, which helps fight off bad bacteria in your gut. Probiotics have shown to support digestion and maintain gut health, and they are also useful at combating inflammation in the body. Talk to your doctor about finding the right probiotic supplement for you.  

As always, if you are experiencing any eye-related concerns—gut-related or otherwise—it’s best to consult with your ophthalmologist as soon as possible. Schedule a comprehensive eye exam today at an FYidoctors clinic near you.