Glaucoma, a progressive vision loss disorder, is now being recognized as a multifaceted disease with various contributing factors. Recent research has revealed that the microbiota, the diverse population of microorganisms in the human body, plays a significant role in glaucoma. Dysbiosis, an imbalance in the composition and function of these microorganisms, has been linked to glaucoma and other human disorders. A meta-study conducted by researchers from West China Hospital-China, Sichuan University-China, and the University of Waterloo-Canada explored the relationship between microbiota and glaucoma, highlighting its impact on aging, obesity, depression, and various locations where dysbiosis can occur.
Aging has long been recognized as a primary risk factor for glaucoma, and changes in the gut microbiota have been observed as individuals age. These changes suggest that specific commensal microbiota may play a crucial role in aging-related diseases like glaucoma. Additionally, obesity has been strongly linked to glaucoma, with obese individuals exhibiting an altered gut microbiota. Dysbiosis in the gut microbiota is considered a risk factor for glaucoma in these individuals. Furthermore, depression and anxiety have also been associated with an increased risk of glaucoma, and patients with depression display dysbiosis in their gut microbiota. These findings indicate that microbiota play a significant role in glaucoma risk factors.
Animal models have provided insights into the relationship between microbiota and glaucoma. Mice and rats with glaucoma exhibit altered gut microbiota, which has been correlated with retinal ganglion cell loss and optic nerve damage. In human patients, studies have revealed differences in the ocular surface, intraocular, oral, gastric, and gut microbiota of glaucoma patients. Dysbiosis in these locations has been linked to glaucoma development, suggesting that microbiota play a role in the pathogenesis of the disease.
Microbes in various locations can influence glaucoma development through the production of metabolites. These metabolites can modulate glaucoma development by affecting retinal ganglion cell health, energy metabolism, and inflammatory responses. Dysbiosis in the oral and ocular surface microbiota can activate the lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4) pathway, which has been implicated in glaucoma pathogenesis. Additionally, microbial peptides that resemble host self-antigens can lead to the generation of autoreactive T-cells and contribute to glaucoma development. Infection with Helicobacter pylori (H. pylori) can impact glaucoma development through the accumulation of homocysteine and inflammation.
Treatment targeting the microbiota may hold potential for helping glaucoma patients. Antibiotics, diet modifications, and fecal microbiota transplantation (FMT) are three main approaches suggested. Antibiotics can inhibit the microbiota and have shown promise in mitigating glaucoma-related inflammation. Diet modifications, such as the MIND diet, have been associated with a reduced incidence of glaucomatous neurodegeneration. FMT, which has been effective in treating other gastrointestinal disorders, may hold potential for restoring a balanced microbiota in glaucoma patients.
In conclusion, the role of microbiota in glaucoma is an exciting and evolving area of research. Dysbiosis in various locations can contribute to glaucoma development through different mechanisms. Understanding this connection offers promise for developing novel therapeutic strategies and personalized treatment approaches. Further research is needed to fully understand the precise mechanisms and interventions, but microbiota have the potential to revolutionize glaucoma management. Taking a holistic approach that considers factors such as diet, mental health, and microbiota composition is crucial in the diagnosis and management of glaucoma. The future of glaucoma research and therapy may indeed lie in the hands of the microbiota.