Food Quality and Design Group, Department of Agrotechnology and Food Sciences, Wageningen University, P.O. Box 17, Wageningen, 6700 AA, The Netherlands.
Host-Microbe Interactomics Group, Department of Animal Sciences, Wageningen University, P.O. Box 17, Wageningen, 6700 AA, The Netherlands.
Mol Nutr Food Res. 2021 Jul;65(13):e2100092. doi: 10.1002/mnfr.202100092. Epub 2021 May 19.
This study aims to investigate the effect of tryptophan sources on tryptophan catabolism by gut microbiota and the aryl hydrocarbon receptor (AhR) activation.
Four substrates (free tryptophan, soybean protein, single and clustered soybean cells) containing an equimolar amount of tryptophan, but with a different bioaccessibility are studied using in vitro batch fermentation. Tryptophan catabolites are identified by LC-MS/MS. AhR activity is measured by HepG2-Lucia AhR reporter cells. The total amount of tryptophan-derived catabolites increases with decreasing level of substrate complexity. Indole is the major catabolite produced from tryptophan and it is the most abundant in the free tryptophan fermentation. Indole-3-acetic acid and indole-3-aldehyde are abundantly generated in the soybean protein fermentation. The soybean cell fermentation produced high concentrations of tryptamine. Interestingly, large amounts of short-chain fatty acids (SCFAs) are also found in the soybean cell and protein fermentation. Both tryptophan-derived catabolites and SCFAs are able to increase AhR reporter activity over time in all four groups.
This study illustrates that bacterial catabolism of tryptophan and resulting AhR activation in the gut is modulated by the food matrix, suggesting a role for food design to improve gut health.
本研究旨在探讨肠道微生物群对色氨酸分解代谢和芳香烃受体（AhR）激活的色氨酸来源的影响。
使用体外批量发酵研究了四种含有等量色氨酸但生物利用度不同的底物（游离色氨酸、大豆蛋白、单一和聚集的大豆细胞）。通过 LC-MS/MS 鉴定色氨酸代谢产物。用 HepG2-Lucia AhR 报告细胞测量 AhR 活性。随着底物复杂性的降低，色氨酸衍生代谢产物的总量增加。吲哚是色氨酸产生的主要代谢产物，在游离色氨酸发酵中含量最多。吲哚-3-乙酸和吲哚-3-乙醛在大豆蛋白发酵中大量生成。大豆细胞发酵产生大量色胺。有趣的是，大豆细胞和蛋白质发酵中也发现了大量短链脂肪酸（SCFAs）。在所有四组中，色氨酸衍生代谢产物和 SCFAs 均可随时间增加 AhR 报告基因活性。
本研究表明，肠道中色氨酸的细菌分解代谢和由此产生的 AhR 激活受食物基质调节，这表明通过食物设计来改善肠道健康的作用。
