Case Control Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2020; 26(45): 7173-7190
Published online Dec 7, 2020. doi: 10.3748/wjg.v26.i45.7173
Alteration of fecal tryptophan metabolism correlates with shifted microbiota and may be involved in pathogenesis of colorectal cancer
Xi-Zhen Sun, Dong-Yan Zhao, Yuan-Chen Zhou, Qian-Qian Wang, Geng Qin, Shu-Kun Yao
Xi-Zhen Sun, Dong-Yan Zhao, Graduate School, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
Xi-Zhen Sun, Dong-Yan Zhao, Yuan-Chen Zhou, Geng Qin, Shu-Kun Yao, Department of Gastroenterology, China-Japan Friendship Hospital, Beijing 100029, China
Yuan-Chen Zhou, Qian-Qian Wang, Peking University China-Japan Friendship School of Clinical Medicine, Peking University, Beijing 100029, China
Author contributions: Sun XZ designed and performed the study, analyzed the data, and drafted the manuscript; Sun XZ, Zhou YC, and Qin G collected the clinical data and fecal samples from the subjects; Zhao DY gave guidance on experiment operation and data interpretation, and contributed to manuscript revision; Yao SK designed the study, supervised the study performance, revised the manuscript, and obtained the funding.
Supported by National Key Research and Development Plan for Precision Medicine Research, No. 2017YFC0910002.
Institutional review board statement: This study was approved by the Ethics Committee of China-Japan Friendship Hospital (No. 2018-116-K85).
Informed consent statement: All patients signed an informed consent form before study enrollment.
Conflict-of-interest statement: All authors report no conflicts of interest.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Shu-Kun Yao, MD, PhD, Professor, Department of Gastroenterology, China-Japan Friendship Hospital, 2nd Yinghua East Road, Chaoyang District, Beijing 100029, China.
Received: September 20, 2020
Peer-review started: September 20, 2020
First decision: September 29, 2020
Revised: October 12, 2020
Accepted: November 2, 2020
Article in press: November 2, 2020
Published online: December 7, 2020
Core Tip

Core Tip: This study comprehensively assessed the profiles of fecal tryptophan (Trp) metabolism in patients with colorectal cancer (CRC) and to explore the potential correlations between the gut microbiome, intestinal barrier function, tissue kynurenine pathway (KP), and alterations in fecal Trp metabolism. We found that CRC gut Trp metabolism was characterized by a decreased Trp indole pathway, which was positively correlated with bowel gut barrier function, and an increased KP in colon tissue. In addition, the decreased indoles-producing bacteria may lead to downregulation of the Trp indole metabolic pathway, allowing more Trp to be metabolized along the KP.