The Human Gut Microbiome as a Screening Tool for Colorectal Cancer

The Human Gut Microbiome as a Screening Tool for Colorectal Cancer

1. Joseph P. Zackular1, 
2. Mary A.M. Rogers2, 
3. Mack T. Ruffin IV3, and
4. Patrick D. Schloss1,*

+Author Affiliations

1. ¹Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan.
2. ²Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan.
3. ³Department of Family Medicine, University of Michigan, Ann Arbor, Michigan.

1. ↵*Corresponding Author:
   Patrick D. Schloss, University of Michigan, 1150 W. Medical Center Dr, 1520A MSRB I, Ann Arbor, MI 48109. Phone: 7346475801; Fax: 7347643562; E-mail:pschloss@umich.edu

Abstract

Recent studies have suggested that the gut microbiome may be an important factor in the development of colorectal cancer. Abnormalities in the gut microbiome have been reported in patients with colorectal cancer; however, this microbial community has not been explored as a potential screen for early-stage disease. We characterized the gut microbiome in patients from three clinical groups representing the stages of colorectal cancer development: healthy, adenoma, and carcinoma. Analysis of the gut microbiome from stool samples revealed both an enrichment and depletion of several bacterial populations associated with adenomas and carcinomas. Combined with known clinical risk factors of colorectal cancer (e.g., BMI, age, race), data from the gut microbiome significantly improved the ability to differentiate between healthy, adenoma, and carcinoma clinical groups relative to risk factors alone. Using Bayesian methods, we determined that using gut microbiome data as a screening tool improved the pretest to posttest probability of adenoma more than 50-fold. For example, the pretest probability in a 65-year-old was 0.17% and, after using the microbiome data, this increased to 10.67% (1 in 9 chance of having an adenoma). Taken together, the results of our study demonstrate the feasibility of using the composition of the gut microbiome to detect the presence of precancerous and cancerous lesions. Furthermore, these results support the need for more cross-sectional studies with diverse populations and linkage to other stool markers, dietary data, and personal health information. Cancer Prev Res; 1–10. ©2014 AACR.

Footnotes

• Note: Supplementary data for this article are available at Cancer Prevention Research Online (http://cancerprevres.aacrjournals.org/).

• Received April 21, 2014.
• Revision received June 4, 2014.
• Accepted June 26, 2014.

• ©2014 American Association for Cancer Research.