polyamine derivatization

多胺是已知影响宿主器官的重要肠道微生物代谢物，然而，肠道微生物组产生多胺的机制仍然知之甚少。在这里，使用稳定同位素分辨代谢组学 （SIRM） 方法跟踪人类粪便微生物组离体中的多胺合成。从新鲜人类粪便中提取活的微生物细胞，并与 ¹³C 标记的菊粉厌氧孵育。通过液相色谱-高分辨率质谱分析样品，追踪¹³种 C 标记代谢物<i>多胺从头</i>。¹³腐胺相比，亚精胺的混合同位素富集度更高，这表明这两种多胺在肠道微生物组中的不同生物合成途径参与其中。SIRM确定了从精氨酸到胍丁胺产生亚精胺的新途径。此外，在小鼠和人类肠道微生物组之间多胺的生物合成中没有发现物种差异。

Polyamines are important gut microbial metabolites known to affect host organs; however, the mechanisms underlying polyamine production by the gut microbiome remain poorly understood. Here, we employed the stable isotope-resolved metabolomics (SIRM) approach to track de novo polyamine synthesis in ex vivo human fecal microbiomes. Live microbial cells were extracted from fresh human feces and anaerobically incubated with ¹³C-labeled inulin. Samples were analyzed via liquid chromatography-high resolution mass spectrometry (LC-HRMS) to trace ¹³C-labeled metabolites for de novo polyamine biosynthesis. SIRM identified a novel pathway for spermidine production from arginine to agmatine. Compared to ¹³C-labeled putrescine, spermidine exhibited higher mixed isotope enrichment, indicating that distinct biosynthetic pathways are involved in the generation of these two polyamines in the gut microbiome. Furthermore, no species-specific differences were detected in polyamine biosynthesis between mouse and human gut microbiomes.