Oral administration of a commercially available probiotic has been found to improve dry eye disease in an animal model.
The findings were presented at ASM Microbe 2023, the annual meeting of the American Society for Microbiology.
Treatment of dry eye usually involves the application of eye drops, gels, or ointment. This new, unconventional treatment involves bacteria in the intestinal tract.
“The ‘friendly’ bacteria that live in the human gastrointestinal tract have been linked to health and protection against disease in many parts of the body, including the gut, brain, and lung,” said presenting author, Dr Laura Schaefer, of Baylor College of Medicine in Houston.1
“It’s therefore not surprising that the gut microbiome also has effects on our eyes.”
Previous work by this research group showed that mice given gut bacteria from human Sjögren syndrome patients with severe dry eye developed worse eye disease than mice that were given gut bacteria from healthy human patients.
This suggests that the gut bacteria from healthy people help to protect the surface of the eye in dry conditions. One possible treatment avenue for dry eye would involve probiotic bacteria that have similar protective effects. The group investigated this by using an orally administered probiotic bacterial strain, Limosilactobacillus reuteri DSM17938, in a dry eye mouse model.
DSM17938 is a human-derived, commercially available probiotic bacterial strain that has already demonstrated protective effects in the gut and immune system in humans and mice, but it has not been tested in the context of eye health.
Mice were first treated with antibiotics, killing many of the ‘friendly’ bacteria living in the gut. They were then exposed to very dry conditions and fed daily doses of either probiotic bacteria or a saline solution as a control.
After five days, the eyes were examined for disease. The mice that were fed the probiotic bacteria had healthier and more intact corneal surfaces. In addition, these mice had more goblet cells – specialised cells that produce mucin, an essential component in tears – in their eye tissue.
Taken together, these data suggest that the right oral probiotic could help treat and manage dry eye symptoms, the researchers said.
Reference
1. American Society for Microbiology (ASM), An oral probiotic can treat dry eye disease (news release), available at: newswise.com/articles/oral-probiotic-offers-potential-treatment-for-dry-eye-disease [accessed 20 June 2023].
