- Researchers have identified a probiotic bacterial strain that helped improve dry eye via a mouse model.
- About 12% of the global population has dry eye, a condition in which the eyes are unable to self-lubricate sufficiently.
- There is no cure for dry eye disease, but the new study presents a pathway for future treatments.
Dry eye is a common condition where the eyes do not make enough
Although there is currently no cure for dry eye disease, there are a number of treatments available to help treat the condition’s symptoms.
Now, researchers from Baylor College of Medicine in Houston, TX have identified a probiotic bacterial strain that helped improve dry eye via a mouse model.
While people may associate tears with crying, healthy eyes produce tears all the time.
Sometimes a person’s eyes may not make enough natural tears, causing dry eye disease. This can happen for a number of reasons, including:
- a dysfunction in the tear film
- tears that evaporate too quickly
ageover 50 years
- taking certain medications, such as
antihistamines environmental issuesincluding smoke, wind, and dry climate eyelid disfiguration
contact lens use
- having certain diseases, including
Sjögren’s syndrome, lupus, rheumatoid arthritis, diabetes, or thyroid disorders.
Symptoms of dry eye disease include:
- burning, stinging, or scratchy feeling in your eyes
- feels like something is in your eye
- mucus in or around the eyes
- light sensitivity
- red or irritated eyes
- difficulty wearing contact lenses
- blurred vision
- excessively watery eyes.
In addition to medical treatments for dry eye, previous research shows that dietary changes may help combat the condition.
According to Dr. Laura Schaefer, assistant professor of molecular virology and microbiology at Baylor College of Medicine in Houston, TX, and lead author of this study, it is important to look for new treatments for dry eye.
“Despite the prevalence of dry eye — approximately 1 in 20 people in the U.S. — there are only a handful of drugs currently available to treat dry eye, and for some patients, these drugs do not work very well to improve symptoms,” she told Medical News Today.
Dr. Schaefer said she and her team decided to focus on looking at a probiotic bacterial strain in the gut to treat dry eye because their
“We performed several experiments using gut bacteria isolated from Sjögren syndrome patients who have severe dry eye, from healthy patients with no eye disease,” she detailed. “When mice are colonized with Sjögren patient gut bacteria, they develop worse dry eye under dry conditions than mice colonized with gut bacteria from healthy patients.”
“This suggests that the gut bacteria from healthy people protect the surface of the eye in dry conditions, and therefore one possible treatment avenue for dry eye would be probiotic bacteria that have similar protective effects,” Dr. Schaefer added.
For this study, Dr. Schaefer and her team utilized a mouse model of dry eye. Mice were first given an antibiotic to kill off “good” bacteria in the gut. They were then exposed to very dry conditions and given either the probiotic bacterial strain,
After 5 days, scientists found the mice given the probiotic bacterial strain had healthier and more intact corneal surfaces than those given the saline solution.
“Our hypothesis was that the probiotic would be protective of the eye, and it was exciting to prove that is true,” Dr. Schaefer said. “This particular probiotic strain, DSM17938, has been well-studied and shown to lower inflammation in other tissues, notably the gut, and improve intestinal barrier function. It has not, however, been evaluated before in the context of the eye.”
“These findings show that bacteria with anti-inflammatory effects in the gut can also reduce inflammatory conditions in the eye. It is known that a healthy diet that is low in harmful fats and high in fiber feeds the ‘good’ bacteria that live in our guts naturally, and the anti-inflammatory effects of these bacteria in the gut can extend to other tissues in the body, including the eye.”
– Dr. Laura Schaefer, lead study author
MNT also spoke with Dr. Benjamin Bert, an ophthalmologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, about this study, in which he was not involved.
“It was actually a pretty fascinating study to see the multi-components that are involved with both our understanding of dry eye and then also our future abilities to treat dry eye,” he commented.
We had seen previously that taking supplements — omega-3 supplements, for example — [was] shown to be beneficial for treating patients with certain types of dry eye. So looking more at the gut microbiome as a potential treatment point is fascinating,” Dr. Bert added.
As for the next steps in this research, he said that as this was conducted via a mouse model, a study in humans would be needed.
“It would be really interesting to see this used as a supplement in a human trial to really prove what their hypothesis is, of this being a significant benefit or a possible treatment that could be used for patients with dry eye,” he added.