Could the health of the eyes be related to the functioning of the intestine? A recent study reveals a unique correlation and the role played by the gut microbiota
Recent findings create hope that antibiotics could potentially treat certain genetic diseases that can lead to blindness.
For genetic eye conditions that lead to blindness, according to a recent study published in Cell, bacteria that escape from the intestine and “travel” to the retina may also be implicated. Until recently, specialists estimated that the eyes are usually protected by a layer of tissue that bacteria cannot penetrate. Therefore, these results are “unexpected” according to Dr. Martin Kriegel, a microbiome researcher at the University of Münster in Germany, who was not involved in the study. “This is a major shift in the paradigm we knew until now,” he adds.
Inherited diseases of the retina, such as retinitis pigmentosa, affect about 5.5 million people worldwide. Mutations in the Crumbs homolog 1 (CRB1) gene are the primary cause of these diseases, some of which lead to blindness. Previous studies have shown that bacteria are not as rare in the eyes as ophthalmologists previously believed, leading the authors of the study to wonder if bacteria cause diseases of the retina, says co-author Dr. Richard Lee, an ophthalmologist then at University College London.
As Dr. Lee and his colleagues found, mutations in CRB1 weaken the bonds between the cells lining the intestine, in addition to the role they have long observed in weakening the protective barrier around the eye. This conclusion prompted the study’s co-author, Dr. Lai Wei, an ophthalmologist at Guangzhou Medical University in China, to create mice with CRB1 mutations with reduced levels of intestinal bacteria. These mice did not show signs of distortion of the cellular layers in the retina, unlike those with typical gut flora.
