The profile of gut microbiota and central carbon-related metabolites in primary angle-closure glaucoma patients

Purpose To explore the profile of gut microbiota and central carbon-related metabolites in patients with primary angle-closure glaucoma (PACG). Methods The fecal microbiotas of 30 PACG patients and 30 healthy participants were detected via 16S rRNA sequencing. Targeted liquid chromatography–mass spectrometry was used to examine serum central carbon-related metabolites. The correlations among metabolites, microbiotas and clinical presentations were also explored. Results Although the α and β diversity between the PACG and control groups did not show a significant difference, the distribution of Blautia and Fusicatenibacter decreased significantly in the PACG group. Functional annotations of microbiota enrichment showed that the most dominant pathway was related to host metabolism. In the PACG patients, seven central carbon metabolites, namely adenosine 5′-diphosphate, dGDP, phosphoenolpyruvic acid, d-ribulose 5-phosphate, d-xylulose 5-phosphate, glucuronic acid, and malonic acid, decreased significantly, whereas two metabolites, citric acid and isocitrate, increased obviously. The mean RNFL thickness was positively correlated with phosphoenolpyruvic acid, the VF-MD was positively correlated with glucuronic acid, and the abundance of Blautia was negatively associated with citric acid. Conclusion Few species of gut microbiota were altered in the PACG patients compared to the healthy subjects. A distinct difference in the phenotype of the central carbon-related metabolites of PACG and their correlation with clinical presentations and microbiota suggests potential mechanisms of RGC impairment and novel intervention targets.