Hefni Mohammed E, Witthöft Cornelia M, Hellström Patrik, Johansson Ingegerd, Esberg Anders
Department of Chemistry and Biomedical Sciences, Linnaeus University, 392 31 Kalmar, Sweden.
Food Industries Department, Faculty of Agriculture, Mansoura University, P.O. Box 46, Mansoura 35516, Egypt.
Metabolites. 2025 May 30;15(6):364. doi: 10.3390/metabo15060364.
: Trimethylamine N-oxide (TMAO) is a gut microbiota-dependent metabolite considered as a risk metabolite for various non-communicable diseases. This study aims to identify differences in the gut microbiota composition and concentrations of TMAO and related metabolites in subjects with and without metabolic syndrome (MetS). : Plasma samples were collected following an overnight fast on two occasions from subjects with (n = 12) and without (n = 21) MetS. Feces samples were collected on the day before the first blood sampling. The gut microbiota was profiled using 16S rRNA full-gene amplification sequencing. TMAO and related methylamines were quantified using UPLC-MSMS. The fasted plasma glucose, plasma lipid profile, and HbA1c were determined, and blood pressure, circumference, height, and weight were measured. : A divergent gut microbiota composition was observed in feces samples from both groups. In contrast to subjects without MetS, subjects with MetS had a reduced microbial diversity, with lower and higher -a pattern associated with (increased) inflammation. Trimethylamine (TMA)-producing bacteria were low in abundance across both groups. While plasma TMAO and related methylamines displayed no significant differences between both groups, L-carnitine was elevated ( = 0.0191) in subjects with MetS. A strong positive correlation was detected between TMAO and TMA ( = 0.439, = 0.003), with a tendency to correlate with carnitine ( = 0.212, = 0.087). : Subjects with MetS were characterized by gut microbiota favoring inflammation-associated species but not TMA producers. This suggests that TMAO may not play a role in MetS subjects without overt comorbidities, e.g., CVD or T2D. The influence of the gut microbiota on early MetS is likely mediated through inflammatory mechanisms driven by specific bacterial shifts rather than TMAO production.
氧化三甲胺（TMAO）是一种依赖肠道微生物群的代谢产物，被认为是多种非传染性疾病的风险代谢物。本研究旨在确定患有和未患有代谢综合征（MetS）的受试者肠道微生物群组成以及TMAO和相关代谢物浓度的差异。：在禁食过夜后，从患有MetS（n = 12）和未患有MetS（n = 21）的受试者中两次采集血浆样本。在首次采血前一天收集粪便样本。使用16S rRNA全基因扩增测序对肠道微生物群进行分析。使用超高效液相色谱-串联质谱法对TMAO和相关甲胺进行定量。测定空腹血糖、血脂谱和糖化血红蛋白，并测量血压、腰围、身高和体重。：在两组受试者的粪便样本中观察到不同的肠道微生物群组成。与未患有MetS的受试者相比，患有MetS的受试者微生物多样性降低，具有与（增加的）炎症相关的较低和较高-a模式。两组中产生三甲胺（TMA）的细菌丰度均较低。虽然两组之间血浆TMAO和相关甲胺没有显著差异，但患有MetS的受试者中左旋肉碱升高（P = 0.0191）。检测到TMAO与TMA之间存在强正相关（r = 0.439，P = 0.003），与肉碱有相关趋势（r = 0.212，P = 0.087）。：患有MetS的受试者的特征是肠道微生物群有利于炎症相关物种而非TMA产生菌。这表明TMAO可能在没有明显合并症（如心血管疾病或2型糖尿病）的MetS受试者中不起作用。肠道微生物群对早期MetS的影响可能是通过特定细菌变化驱动的炎症机制介导的，而不是通过TMAO的产生。
