Gut Microbiota Profiles in Myopes and Non-Myopes

Purpose: To identify compositional differences in the gut microbiome of non-myopes and myopes using 16S ribosomal RNA (rRNA) sequencing and to investigate whether the microbiome may contribute to the onset or progression of the condition.
Methods: Faecal samples were collected from 52 adult participants, of whom 23 were non-myopes (NM), 8 were progressive myopes (PM) and 21 were stable myopes (SM). The composition of the gut microbiota in each group was analysed using 16S rRNA gene sequencing.
Results: There were no significant differences in alpha and beta diversity between the three groups (NM, PM and SM). However, the distributions of Bifidobacterium, Bacteroides, Megamonas, Faecalibacterium, Coprococcus, Dorea, Roseburia, and Blautia were significantly higher in the myopes (SM and PM combined) when compared to emmetropes. The myopes exhibited significantly higher abundance of bacteria that are linked to the regulation of dopaminergic signalling, such as Clostridium, Ruminococcus, Bifidobacterium, and Bacteroides. Individuals with stable myopia were found to have a significantly higher proportion of Prevotella copri than those with progressive myopia. Bifidobacterium adolescentis, a gamma-aminobutyric acid (GABA)-producing bacterium, was significantly higher in all myopes than in NM and in the comparison between SM and PM it is significantly higher in SM. B. uniformis and B. fragilis, both GABA-producing Bacteroides, were present in relatively high abundance in all myopes and in SM compared to PM, respectively.
Conclusion: The presence of bacteria related to dopamine effect and GABA-producing bacteria in the gut microbiome of myopes may suggest a role of these microorganisms in the onset and progression of myopia.