Abstract
Purpose :
One mechanism implicated in the development and progression of myopia is the role of dopamine and gamma-aminobutyric acid (GABA). Dopamine and GABA are neurotransmitters known to be produced in the retina and by bacteria in the gut. This research investigated if there was a difference in the composition of the gut microbiome between myopes and emmetropes, as such a finding may suggest a potential role in myopia development.
Methods :
52 adults participated in the study. 23 participants were emmetropic, and 29 were myopic (eight 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 from faecal samples. Visual acuity, refractive error, and axial length measurements were also collected, and microbiome data were processed using the Phyloseq R package and analysed with QIIME 2.0 and DADA2 for de-noising steps. Differential abundance analysis was performed using the DESeq2 package and DESeq function, with the threshold for significant differences between taxa set at p <0.01.
Results :
No significant differences were found in alpha and beta diversity between myopes and emmetropes (p>0.05). The abundance of Bacteroides, Bifidobacterium, Blautia, Coprococcus, Dorea, Faecalibacterium, Megamonas, and Roseburia was significantly higher in myopes than in emmetropes. Myopes had a significantly higher abundance of bacteria associated with the modulation of dopaminergic signalling, such as Bacteroides, Bifidobacterium, Clostridium, and Ruminococcus. The abundance of Bifidobacterium adolescentis, a bacterial species that produces GABA, was significantly higher in the myopes than in the emmetropes. Furthermore, myopes also had higher levels of other GABA-producing bacteria: Bacteroides fragilis.
Conclusions :
Our findings showed differences in the gut microbiome of myopes and emmetropes. The presence of dopamine- and GABA-producing bacteria could play an important role in the development and progression of myopia.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.