Next Generation Science Institute, RD Division, Morinaga Milk Industry Co., Ltd., Zama, Japan.
Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi, Japan.
Commun Biol. 2021 May 10;4(1):541. doi: 10.1038/s42003-021-02072-7.
This study aims to understand the mechanistic basis underlying the response of Bifidobacterium to lactulose ingestion in guts of healthy Japanese subjects, with specific focus on a lactulose transporter. An in vitro assay using mutant strains of Bifidobacterium longum subsp. longum 105-A shows that a solute-binding protein with locus tag number BL105A_0502 (termed LT-SBP) is primarily involved in lactulose uptake. By quantifying faecal abundance of LT-SBP orthologues, which is defined by phylogenetic analysis, we find that subjects with 10 to 10 copies of the genes per gram of faeces before lactulose ingestion show a marked increase in Bifidobacterium after ingestion, suggesting the presence of thresholds between responders and non-responders to lactulose. These results help predict the prebiotics-responder and non-responder status and provide an insight into clinical interventions that test the efficacy of prebiotics.
本研究旨在了解健康日本受试者肠道中双歧杆菌对乳果糖摄入反应的机制基础，特别关注乳果糖转运蛋白。使用双歧杆菌长亚种 105-A 的突变株进行的体外分析表明，具有基因座标签编号 BL105A_0502 的溶质结合蛋白（称为 LT-SBP）主要参与乳果糖的摄取。通过定量分析通过系统发育分析定义的每克粪便中 LT-SBP 同源物的丰度，我们发现，在摄入乳果糖之前，粪便中每克粪便的基因数量为 10 到 10 拷贝的受试者在摄入乳果糖后双歧杆菌明显增加，这表明对乳果糖的应答者和非应答者之间存在阈值。这些结果有助于预测益生菌应答者和非应答者的状态，并为测试益生菌功效的临床干预提供了深入了解。
