Urine-based metabolomics-driven strategies for the discovery of biomarkers are increasingly developed and applied in analytical chemistry. But valid, data-based recommendations for a urine sample material of choice are lacking. We investigated first and second morning urine (MU), which are the most commonly used urine specimens. Potential major factors biasing metabolomics biomarker results in these sample materials were studied. First, 35 1st and 2nd MU samples were collected from healthy, young men after an overnight fast. Subsequently, two subgroups were built, one having fast food at lunch and dinner (n = 17), the other vegetarian meals (n = 18). Again 1st and 2nd MU were collected. Non-targeted liquid chromatography-mass spectrometry was applied for analyses. More than half of the >5400 urinary ion features showed a significant difference between 1st and 2nd MU. Just two fast food meals on previous day significantly affected around 30% of all metabolites in 1st and 2nd MU. In contrast, the effects of two vegetarian meals in 2nd MU were only minor. Additionally, we describe 47 metabolites in urine, possible hits in biomarker studies, which are susceptible to the diet the day before sample collection. They should be handled with caution until validation in diet-controlled studies. Based on our results we think the second MU, ideally collected after standardized vegetarian meals and drinking only water on the previous day, is most suitable for valid analysis of biomarkers in urine.

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哪种尿液样本材料是代谢组学驱动的生物标志物研究的首选？

用于发现生物标志物的基于尿液的代谢组学驱动的策略越来越多地开发并应用于分析化学。但是缺乏针对尿液样本材料选择的基于数据的有效建议。我们调查了第一次和第二次晨尿 (MU)，这是最常用的尿液样本。研究了影响这些样品材料中代谢组学生物标志物结果的潜在主要因素。首先，在禁食一夜后，从健康的年轻男性身上收集了 35 个第 1 和第 2 MU 样本。随后，建立了两个子组，一个在午餐和晚餐时吃快餐（n = 17），另一个吃素食（n = 18）。再次收集了第 1 个和第 2 个 MU。非靶向液相色谱-质谱法用于分析。超过一半 > 5400 尿离子特征显示第 1 和第 2 MU 之间存在显着差异。前一天仅吃两顿快餐就显着影响了第 1 和第 2 MU 中约 30% 的所有代谢物。相比之下，第二个 MU 中两次素食的影响很小。此外，我们还描述了尿液中的 47 种代谢物，这些代谢物可能是生物标志物研究中的结果，它们很容易受到样本收集前一天饮食的影响。在饮食控制研究中得到验证之前，应谨慎处理它们。根据我们的结果，我们认为第二个 MU 最好在标准化素食餐后收集，并且在前一天只喝水，最适合对尿液中的生物标志物进行有效分析。在第二个 MU 中两次素食的影响很小。此外，我们还描述了尿液中的 47 种代谢物，这些代谢物可能是生物标志物研究中的结果，它们很容易受到样本收集前一天饮食的影响。在饮食控制研究中得到验证之前，应谨慎处理它们。根据我们的结果，我们认为第二个 MU 最好在标准化素食餐后收集，并且在前一天只喝水，最适合对尿液中的生物标志物进行有效分析。在第二个 MU 中两次素食的影响很小。此外，我们还描述了尿液中的 47 种代谢物，这些代谢物可能是生物标志物研究中的结果，它们很容易受到样本收集前一天饮食的影响。在饮食控制研究中得到验证之前，应谨慎处理它们。根据我们的结果，我们认为第二个 MU 最好在标准化素食餐后收集并且在前一天只喝水，最适合对尿液中的生物标志物进行有效分析。