Metabolome and microbiome alterations in tongue coating of gastric precancerous lesion patients

<b>Objective</b>: This paper seeks to provide mechanistic insight into the pathological transition through the analysis of metabolites and microorganisms in the tongue coating of gastric precancerous lesions (GPL) patients. <b>Methods</b>: GC-TOF-MS and UHPLC-QE-MS metabolomics, combined with 16S rRNA microbiome techniques, were performed to explore the changes in metabolites and microorganisms in the tongue coating of GPL patients. <b>Results</b>: When compared with 15 controls, 133 metabolites were found to be differentially expressed in 60 GPL cases, of which could be divided into ten categories. Among them, most of the differentially expressed metabolites identified were lipids or lipid-like molecules. These metabolites were implicated in 6 metabolic pathways including glycine, serine and threonine metabolism, arginine and proline metabolism, sphingolipid metabolism, valine, leucine and isoleucine degradation, arachidonic acid metabolism, and tyrosine metabolism. The relative abundances of Alloprevotella, Solobacterium, Rothia, Eikenella, and Aggregatibacter in the GPL group increased significantly relative to the controls and were associated with lipids and lipid-like molecules, organic nitrogen compounds, organic oxygen compounds, phenylpropanoids and polyketides, and organoheterocyclic compounds, respectively. <b>Conclusions</b>: Compared with healthy people, the changes of tongue coating metabolites in GPL patients were mainly characterized by alterations in lipid metabolism and were associated with localized changes in the microbiome.

**研究目的**：本研究旨在通过分析胃黏膜癌前病变（gastric precancerous lesions, GPL）患者舌苔中的代谢物与微生物，为其病理转归提供机制层面的解析。**研究方法**：采用气相色谱-飞行时间质谱（GC-TOF-MS）、超高效液相色谱-静电场轨道阱质谱（UHPLC-QE-MS）代谢组学技术，联合16S核糖体RNA（16S rRNA）微生物组学技术，探究GPL患者舌苔中代谢物与微生物的变化特征。**研究结果**：与15例健康对照者相比，60例GPL患者的舌苔中共筛选出133个差异表达代谢物，可分为10大类。其中，鉴定出的差异代谢物多为脂质及类脂质分子。这些代谢物涉及6条代谢通路，包括甘氨酸、丝氨酸和苏氨酸代谢、精氨酸和脯氨酸代谢、鞘脂代谢、缬氨酸、亮氨酸和异亮氨酸降解、花生四烯酸代谢以及酪氨酸代谢。GPL组中Alloprevotella、Solobacterium、Rothia、Eikenella及Aggregatibacter的相对丰度较对照组显著升高，且分别与脂质及类脂质分子、有机氮化合物、有机含氧化合物、苯丙烷类与聚酮类化合物以及有机杂环化合物相关。**结论**：与健康人群相比，GPL患者舌苔代谢物的变化主要以脂质代谢紊乱为特征，并与微生物组的局部改变相关。