Study: Blindness from Some Inherited Eye Diseases May be Caused by Gut Bacteria

Sight loss in certain inherited eye diseases may be caused by gut bacteria, and is potentially treatable by antimicrobials, according to a new study in mice co-led by a University College London (UCL) and Moorfields researcher. 

The international study observed that in eyes with sight loss caused by a particular genetic mutation, known to cause eye diseases that lead to blindness, gut bacteria were found within the damaged areas of the eye. The authors of the new paper, published in Cell and jointly led by researchers in China, say their findings suggest that the genetic mutation may relax the body’s defences, thus allowing harmful bacteria to reach the eye and cause blindness, according to an article posted on the UCL website.

The researchers were investigating the impact of the Crumbs homolog 1 (CRB1) gene, which is known to be expressed in the retina and is crucial to building the blood-retina barrier to regulate what flows in and out of the eye. The CRB1 gene is associated with inherited eye disease, most commonly forms of Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP); the gene is the cause of 10% of LCA cases and 7% of RP cases worldwide.

Using mouse models, the research team discovered the CRB1 gene is key to controlling the integrity of the lower gastrointestinal tract, the first ever such observation. There, it combats pathogens and harmful bacteria by regulating what passes between the contents of the gut and the rest of the body.

Read the full UCL article here. Access the full study in Cell here.