Probiotic may hold key to treating dry eye disease

It’s a painful eye condition with no cure that affects thousands of Aussies, particularly older people. But relief for dry eye syndrome could be as easy as taking a probiotic, research has found.

Dry eye disease (DED) is a common condition that can have a significant effect on your quality of life. Dry eyes can make your eyes feel sore and gritty and make your vision blurry.

The symptoms of DED vary from person to person. People suffering from dry eye disease often report feeling sensitive to light, causing red eyes that sting and burn. Sometimes DED can cause excess tearing and/or blepharitis (inflamed eyelids).

DED is caused mainly by faulty tear ducts not producing enough tears to keep your eyes lubricated. If left undiagnosed and untreated, dry eye can lead to eye infections and potential damage to the cornea, the surface of the eye. In severe cases, corneal damage can even result in vision loss.

Although there is no cure for DED, there are a number of treatments for the condition including eye drops and prescription medications.

Now, a team of researchers from Baylor College of Medicine in the US have identified a probiotic bacterial strain that may have the potential to improve DED symptoms even further.

Previous research suggested that dietary changes may help combat dry eye disease, including a 2019 study that found omega-3 supplements significantly improved dry eye symptoms and signs.

Dr Laura Schaefer, lead author of the study, told Medical News Today her team was inspired by these, and other similar findings, to find a probiotic strain that could better treat DED as there was clearly a link between DED and gut health.

Dr Schaefer and her team injected one group of mice with gut bacteria taken from human patients with severe dry eye and another group with bacteria from healthy patients. They found the mice injected with the DED bacteria also went on to develop DED, but the other group did not.

“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 says.

In a new experiment, the researchers then took another two groups of mice, feeding one group the probiotic Limosilactobacillus reuteri and the other with a saline solution as a control.

After five days, scientists found the mice given the probiotic bacterial strain had healthier and more intact corneal surfaces than those given the saline solution.

Additionally, the mice given the probiotic had higher levels of cells called goblet cells in their eyes. These cells are essential for tear production and produce a substance known as mucin.

“These findings show that bacteria with anti-inflammatory effects in the gut can also reduce inflammatory conditions in the eye,” Dr Schaefer says.

“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.”

The results show a potential pathway for the development of new treatments for dry eye that focus on the gut. As this study was conducted on mice, the next step is to do the tests on humans to see if the results can be replicated.

Do you suffer from dry eye disease? How do you treat the symptoms? Let us know in the comments section below.

Also read: Vision problems can lead to brain health misdiagnosis