State Key Laboratory of Microbial Metabolism, School of Pharmacy, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Minhang District, Shanghai 200240, China.
Université de Pau, CNRS, Institute of Analytical and Physical Chemistry for the Environment and Materials, IPREM-UMR5254, Hélioparc, Pau 64053, France.
J Agric Food Chem. 2022 Jun 8;70(22):6726-6736. doi: 10.1021/acs.jafc.2c01409. Epub 2022 May 24.
Selenium (Se)-enriched probiotics are potential sources of organic Se in the human diet, but their application in food is debated because most selenized probiotics and their metabolites are not well-characterized. We analyzed a Se-enriched probiotic, DD98, to unveil its Se metabolite profiles by two-dimensional high-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP MS) and HPLC-electrospray ionization Orbitrap MS. A major Se metabolite was identified as gamma-glutamyl-selenomethionine (γ-Glu-SeMet), which accounted for 42.5 ± 3.4% of water-soluble Se. Most of the remaining Se was present as SeMet (35.2 ± 0.6%) in a free or protein-bound form. In addition, 11 minor Se metabolites were identified, eight of which had not been reported before in probiotics. Six of the identified compounds contained γ-Glu-SeMet as the core structure, constituting a γ-Glu-SeMet family. This study demonstrates the presence of γ-Glu-SeMet in a probiotic, showing a different selenite metabolite pathway from that of Se-enriched yeast, and it offers an alternative and potentially attractive source of organic Se for food and feed supplementation.
富硒益生菌是人类饮食中有机硒的潜在来源，但它们在食品中的应用仍存在争议，因为大多数硒化益生菌及其代谢物尚未得到很好的表征。我们分析了一种富硒益生菌 DD98，通过二维高效液相色谱电感耦合等离子体质谱（HPLC-ICP MS）和高效液相色谱-电喷雾电离轨道阱质谱（HPLC-ESI Orbitrap MS）揭示其硒代谢产物谱。鉴定出一种主要的硒代谢产物为γ-谷氨酰-硒代蛋氨酸（γ-Glu-SeMet），占水溶性硒的 42.5±3.4%。其余大部分硒以游离或蛋白结合形式存在的硒代蛋氨酸（35.2±0.6%）形式存在。此外，还鉴定出 11 种微量硒代谢产物，其中 8 种以前在益生菌中未报道过。鉴定出的化合物中有 6 种含有γ-Glu-SeMet 作为核心结构，构成了一个γ-Glu-SeMet 家族。本研究表明益生菌中存在γ-Glu-SeMet，其亚硒酸盐代谢途径与富硒酵母不同，为食品和饲料补充提供了一种替代的、潜在有吸引力的有机硒来源。
