Trust Your Gut

When asked to think of an ecosystem with over 1,000 different species, a tropical rainforest or a coral reef might spring to mind. A few of you may immediately think of the biological party platter that resides in your gut, which acts as a cozy home to trillions of microbes that keep us ticking over. Many people – and some doctors – would be forgiven for thinking that, because these microbes inhabit our intestines, their only impact is on gastrointestinal health. However, our gut microbiome is also crucial to the health of other organs of the body – including the eyes! This interaction, in which a balance exists between gut wildlife and healthy function and disease in the eyes, is called the gut-eye axis. A shift in the contents or health of the gut microbiome can throw off this balance, inducing or exacerbating ophthalmic diseases such as uveitis, AMD, diabetic retinopathy, or retinitis pigmentosa (RP).

A research team from Spain’s University of Alicante have found that, in mice, retinal degeneration in RP is associated with specific changes in the gut microbiome (1). In particular, four common microbe genera – Rikenella, Muribaculaceace, Prevotellaceae UCG-001, and Bacilli – are missing in mice with retinal disease, whereas Bacteroides caecimuris is heavily enriched. This indicates that measuring shifts in microbiome composition could offer a simple biomarker of RP and other retinal diseases, as well as suggesting the gut-eye axis as a potential therapeutic target.

This research adds to previous evidence that the gut microbiome is important in a wide variety of disease states and warrants further research into the balance of the gut-eye axis.