Case Control Study
Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2025; 31(13): 105248
Published online Apr 7, 2025. doi: 10.3748/wjg.v31.i13.105248
Altered microbiota of rectal mucosa in rectal cancer patients
Hao Zhang, Yan Zhou, You-Heng Jiang, Wan-Ping Hu, Lu-Lu Huang, Hai-Xia Lin, Zhi-Gui Zuo, Ji-Mei Du, Yong-Liang Lou
Hao Zhang, Department of Laboratory Medicine, Hangzhou Geriatric Hospital, Hangzhou 310022, Zhejiang Province, China
Hao Zhang, Yan Zhou, Lu-Lu Huang, Hai-Xia Lin, Ji-Mei Du, Yong-Liang Lou, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
You-Heng Jiang, Tomas Lindahl Nobel Laureate Laboratory, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen 518107, Guangdong Province, China
Wan-Ping Hu, Zhi-Gui Zuo, Department of Colorectal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325035, Zhejiang Province, China
Co-corresponding authors: Ji-Mei Du and Yong-Liang Lou.
Author contributions: Lou YL and Zhang H are responsible for funding acquisition; Zhang H, Zhou Y, Lin HX, and Jiang YH contributed to study conceptualization; Zuo ZG, Du JM, and Lou YL supervised the study; Zhang H and Du JM wrote, reviewed and edited the manuscript; Lou YL performed project management; Zhang H, Zhou Y, Jiang YH, Hu WP, and Huang LL participated in the data curation and investigation; Zhang H and Hu WP contributed to the methodology of this study; Zhou Y is responsible for original draft preparation; Zuo ZG is responsible for resources; Zuo ZG and Du JM were involved in project administration; Du JM and Lou YL contributed equally to this work as co-corresponding authors; and all authors were involved in the critical review of the results and have contributed to, read, and approved the final manuscript.
Supported by the Medical and Health Research Project of Zhejiang Province, No. 2023KY998.
Institutional review board statement: This work was approved by the First Affiliated Hospital of Wenzhou Medical University, No. 2020-127.
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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.
Data sharing statement: The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: National Center for Biotechnology Information (NCBI) BioProject, https://www.ncbi.nlm.nih.gov/bioproject/, PRJNA1201090 and PRJNA644453.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yong-Liang Lou, Professor, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Chashan Street, Wenzhou 325035, Zhejiang Province, China. lyl@wmu.edu.cn
Received: January 16, 2025
Revised: February 27, 2025
Accepted: March 21, 2025
Published online: April 7, 2025
Processing time: 76 Days and 22.1 Hours
Abstract
BACKGROUND

With advances in sequencing techniques, microbiota dysbiosis and pathogenic microbes that accelerate colorectal cancer progression have been identified and widely reported. However, few studies have focused on the microbiota taxa of rectal mucus in rectal cancer (RC) patients. Here, we analyzed the composition and characteristics of the rectal mucosa microbiota of RC patients from Wenzhou city, China, and compared the results with those of healthy controls.

AIM

To explore the changes in the characteristics of the rectal mucosal flora associated with RC, and identify biomarkers of microbe taxa for RC.

METHODS

Rectal mucosa samples from a Chinese cohort of 72 recently diagnosed RC patients and 71 healthy controls were obtained. A validation cohort, which included 22 RC patients and 60 healthy controls, was also established. Changes in the rectal mucosal flora were observed by cultivation, 16S ribosomal DNA gene sequencing analysis and quantitative polymerase chain reaction analysis.

RESULTS

The 16S ribosomal DNA results demonstrated that RC patients presented increased bacterial community richness and alpha diversity as well as an altered rectal mucosal microbiota, with depletion of Proteobacteria and Thermi and enrichment of Bacteroidetes and Fusobacteria in cancerous mucosal tissues (CM) and enrichment of Firmicutes and Cyanobacteria in adjacent noncancerous mucosal tissues (AM). The culture results showed that the mean loads of Escherichia coli, Bifidobacterium, Enterococcus, and Lactobacillus were significantly reduced in RC patients. The ratios of Prevotella to Ruminococcus [areas under the receiver operating curve: 0.795 in AM vs normal control mucosa (NM), 0.77 in CM vs NM] and of Prevotella stercorea to Propionibacterium acnes (areas under the receiver operating curve: 0.808 in AM vs NM, 0.843 in CM vs NM) exhibited excellent abilities to differentiate between healthy controls and RC patients.

CONCLUSION

RC patients have an altered rectal mucosal microbiota, and the ratio of Prevotella to Ruminococcus or the ratio of Prevotella stercorea to Propionibacterium acnes may serve as a marker for RC diagnosis.

Keywords: Rectal cancer; Mucosal-associated microbiota; Gut microbiota; Genomics; Predictive biomarkers

Core Tip: In this study, we focused on the rectal mucosal microbiota, which is associated with the occurrence and development of rectal cancer (RC). Although the gut microbiota is commonly studied in patients with colorectal cancer, but few studies have focused on RC, especially the microbiota of the rectal mucus. Our research revealed that RC patients had an altered rectal mucosal microbiota; characterized by enrichment of Bacteroidetes, Fusobacteria and Firmicutes; and depletion of Proteobacteria and Thermi. The Prevotella/Ruminococcus ratio and the Prevotella stercorea/Propionibacterium acnes in the rectal mucosal microbiota may serve as a marker for RC diagnosis.