Patients with primary open-angle glaucoma (POAG) may have different gut microbes than healthy individuals, suggesting metabolism may play a part, ultimately leading to the development of the disease, a study in Experimental Eye Research reports.

Gut microbiota and its influence on metabolism are considered an environmental factor that contributes to the progression of many immune and neurodegenerative diseases, but their potential influence in POAG is not clearly established.

In the current study, a team of Chinese researchers examined serum samples and the genes of bacteria from 30 POAG patients and 30 healthy subjects.

Compared with controls, POAG patients had a different gut microbe makeup. Specifically, the subjects with POAG had more Prevotellaceae,

Enterobacteriaceae and Escherichia coli, but a decreased level of Megamonas and Bacteroides plebeius. 

Additionally, POAG patients had unique metabolic profiles when compared with the control group. This included five amino acids or dipeptides, two hormone derivatives, one purine derivative, one bile acid derivative and one organic acid. The results also show citric acid was positively correlated with Megamonas, whereas L-γ-Glutamyl-L-alanine, MHPG, cholic acid glucuronide and hypoxanthine were negatively correlated with Megamonas.

The presence of certain bacteria was also linked to visual acuity and the structure of the eye. The study found negative correlations between visual acuity and Blautia, and visual field mean deviation and Faecalibacterium, and a positive correlation between retinal nerve fiber layer thickness and Streptococcus. 

These finding suggests gut microbiota and serum metabolites may be tied to the pathogenesis of glaucoma and could provide new insight into gut microbiota-targeted interventions of the disease, they added.