Zhang Shi-Min, Wu Hui-Chu, Hung Jia-He, Huang Shir-Ly
Program in Molecular Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Microb Biotechnol. 2025 Jun;18(6):e70167. doi: 10.1111/1751-7915.70167.
The metabolic processes of Bifidobacterium longum subsp. infantis, an early coloniser of the human gut, are essential for gut health, mainly due to the production of indole derivatives from tryptophan. This study investigates the capacity of B. infantis ATCC 15697 to biosynthesise indole-3-lactate (ILA), indole-3-acetate (IAA), and indole-3-carboxaldehyde (I3CA) and the regulatory effects of substrate availability on these pathways. The tryptophan catabolic profile of B. infantis ATCC 15697 under a non-growing but metabolically active state was investigated. Through HPLC-PDA and LC-MS analyses, we confirmed for the first time the production of IAA and I3CA by B. infantis ATCC 15697. The results revealed a dose-dependent relationship between tryptophan availability and the production of indole derivatives, highlighting the nutrient-driven effect of these metabolic pathways. By integrating genomic analysis with metabolic profiles, we proposed potential pathways underlying the biosynthesis of IAA and I3CA from tryptophan. These findings enhance our understanding of the role of B. infantis ATCC 15697 in human health, with ILA, IAA, and I3CA contributing to immune modulation and gut health. We also provide a platform for using B. infantis ATCC 15697 as a biocatalyst for the biosynthesis of beneficial indole derivatives through whole-cell bioconversion, which was further demonstrated in B. infantis ATCC 25962 and ATCC 15702. Future in vivo studies will help clarify the impact of these metabolites on the gut environment and inform dietary and probiotic strategies for enhancing indole derivatives production.
婴儿双歧杆菌亚种是人类肠道的早期定植菌，其代谢过程对肠道健康至关重要，这主要归因于它能从色氨酸产生吲哚衍生物。本研究调查了婴儿双歧杆菌ATCC 15697生物合成吲哚 - 3 - 乳酸（ILA）、吲哚 - 3 - 乙酸（IAA）和吲哚 - 3 - 甲醛（I3CA）的能力，以及底物可用性对这些途径的调节作用。研究了处于非生长但代谢活跃状态下的婴儿双歧杆菌ATCC 15697的色氨酸分解代谢谱。通过高效液相色谱 - 光电二极管阵列检测（HPLC - PDA）和液相色谱 - 质谱（LC - MS）分析，我们首次证实了婴儿双歧杆菌ATCC 15697能产生IAA和I3CA。结果揭示了色氨酸可用性与吲哚衍生物产生之间的剂量依赖性关系，突出了这些代谢途径的营养驱动效应。通过将基因组分析与代谢谱相结合，我们提出了从色氨酸生物合成IAA和I3CA的潜在途径。这些发现增进了我们对婴儿双歧杆菌ATCC 15697在人类健康中作用的理解，ILA、IAA和I3CA有助于免疫调节和肠道健康。我们还提供了一个平台，可利用婴儿双歧杆菌ATCC 15697作为生物催化剂，通过全细胞生物转化来生物合成有益的吲哚衍生物，这在婴儿双歧杆菌ATCC 25962和ATCC 15702中得到了进一步证实。未来的体内研究将有助于阐明这些代谢物对肠道环境的影响，并为增强吲哚衍生物产生的饮食和益生菌策略提供依据。
