The gut microbiota–derived metabolite trimethylamine N-oxide (TMAO) has been regarded as one of the potent risk factors of cardiovascular events and diabetes. However, its association with possible inflammatory mediators has not been revealed yet. In the current meta-analysis, we quantitatively summarized the results of studies regarding the association between TMAO and inflammation. Electronic databases including PubMed, ProQuest, Scopus, and Embase were systematically searched and a total of 586 manuscripts were retrieved. After removing 223 duplicates, 363 manuscripts were reviewed. All of the studies regarding the association between TMAO and inflammatory factors were included in the systematic review and eligible studies were included in to the meta-analysis. Accordingly, 13,783 number of participants were included and the results showed that being in the highest category of TMAO Accordingly was associated with 0.27 mg/L (weighted mean difference: 0.268; 95% confidence interval [CI]: 0.058–0.479; p = 0.013) increase in CRP concentrations compared with lowest category. The results of subgrouping and meta-regression revealed the location, CRP sample source, disease status, male percent, proportion of diabetes and smoking as the source of heterogeneity. Moreover, the dose-response meta-analysis revealed a non-linear association between increased TMAO concentrations and increased CRP concentrations (p for nonlinearity = 0.015). To our knowledge, this is first dose-response meta-analysis that summarized the results of studies about the association between circulating TMAO concentrations and inflammation risk.

肠道菌群衍生的代谢物三甲胺N氧化物（TMAO）被认为是心血管事件和糖尿病的潜在危险因素之一。然而，其与可能的炎性介质的关联尚未被揭示。在当前的荟萃分析中，我们定量地总结了有关TMAO与炎症之间关系的研究结果。系统搜索了包括PubMed，ProQuest，Scopus和Embase在内的电子数据库，共检索到586篇手稿。删除223个重复项目后，对363个手稿进行了审查。所有有关TMAO和炎症因子之间关系的研究均纳入系统评价，符合条件的研究也纳入荟萃分析。因此，13p  = 0.013）与最低类别相比CRP浓度增加。分组和荟萃回归的结果揭示了异质性的来源，位置，CRP样本来源，疾病状况，男性百分比，糖尿病和吸烟比例。此外，剂量反应荟萃分析显示，TMAO浓度增加和CRP浓度增加之间存在非线性关系（非线性p = 0.015）。据我们所知，这是首次剂量反应荟萃分析，总结了关于循环TMAO浓度与炎症风险之间关系的研究结果。