The gut microbiota (GM) and its influence on host metabolism are considered to be an environmental factor that contributes to the progression of many immune and neurodegenerative diseases. However, the features of the GM and serum metabolites in Primary open-angle glaucoma (POAG) patients have not been clearly elucidated. The purpose of this research is to explore the gut microbial composition and serum metabolic phenotype in POAG patients. 16S rRNA V4 genes of bacteria from the fecal samples of 30 POAG patients and 30 healthy subjects were sequenced by the Illumina MiSeq platform and then analyzed by QIIME. Their serum samples were analyzed by gas chromatography/mass spectrometry (GC-MS)-based metabolomics. The association between gut microbial species and host circulating metabolites and clinical phenotypes was also analyzed. Compared with controls, f Prevotellaceae, g unidentified Enterobacteriaceae, and s Escherichia coli increased the most in POAG patients, whereas g Megamonas and s Bacteroides plebeius significantly decreased in POAG patients. The alteration of the endogenous metabolomic profile in POAG patients included five amino acids or dipeptides, two hormone derivates, one purine derivative, one bile acid derivative and one organic acid. It also showed that citric acid was positively correlated with Megamonas, whereas L-γ-Glutamyl-L-alanine, MHPG, cholic acid glucuronide and hypoxanthine were negatively correlated with Megamonas. Mean visual acuity was negatively correlated with Blautia, mean VF-MD was negatively correlated with Faecalibacterium, and average RNFL thickness was positively correlated with Streptococcus. Our results revealed that there was a distinct difference in GM composition and serum metabolic phenotype between POAG patients and healthy individuals. This finding suggests the potential correlations between the GM and serum metabolites in the pathogenesis of glaucoma and thus provides new insight into the GM-targeted interventions of this disease.

中文翻译：

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原发性开角型青光眼患者肠道菌群组成特征和血清代谢表型。

肠道菌群（GM）及其对宿主代谢的影响被认为是导致许多免疫和神经退行性疾病发展的环境因素。然而，尚未明确阐明原发性开角型青光眼（POAG）患者的GM和血清代谢产物的特征。这项研究的目的是探讨POAG患者的肠道微生物组成和血清代谢表型。用Illumina MiSeq平台对来自30名POAG患者和30名健康受试者粪便样品中细菌的16S rRNA V4基因进行测序，然后通过QIIME进行分析。通过基于气相色谱/质谱（GC-MS）的代谢组学分析他们的血清样品。还分析了肠道微生物种类与宿主循环代谢产物和临床表型之间的关系。与对照组相比，POAG患者中的前鞭毛纲科，g未鉴定的肠杆菌科和大肠杆菌增加最多，而POAG患者中的g大单胞菌和s Bacteroides plebeius显着减少。POAG患者内源性代谢组学特征的变化包括5种氨基酸或二肽，2种激素衍生物，1种嘌呤衍生物，1种胆汁酸衍生物和1种有机酸。还表明柠檬酸与大摩纳哥呈正相关，而L-γ-谷氨酰-L-丙氨酸，MHPG，胆酸葡萄糖醛酸和次黄嘌呤与大摩纳哥呈负相关。平均视力与蓝藻呈负相关，平均VF-MD与Faecalibacterium呈负相关，平均RNFL厚度与链球菌呈正相关。我们的结果表明，POAG患者和健康个体之间的GM组成和血清代谢表型存在明显差异。这一发现表明，青光眼发病机制中的GM和血清代谢物之间存在潜在的相关性，从而为以GM为目标的对该疾病的干预提供了新的见识。