Review
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2022; 28(25): 2782-2801
Published online Jul 7, 2022. doi: 10.3748/wjg.v28.i25.2782
Inflammation, microbiome and colorectal cancer disparity in African-Americans: Are there bugs in the genetics?
Sami Ahmad, Hassan Ashktorab, Hassan Brim, Franck Housseau
Sami Ahmad, Franck Housseau, Department of Oncology, Johns Hopkins University, Baltimore, MD 21231, United States
Hassan Ashktorab, Department of Medicine, Howard University, Washington, DC 20060, United States
Hassan Brim, Department of Pathology, Howard University, Washington, DC 20060, United States
Author contributions: Ahmad S wrote the manuscript; Housseau F and Brim H contributed equally to the review’s conception and oversight of the writing, with additional insight from Ashktorab H; and all authors have read and approve the final manuscript.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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: Franck Housseau, PharmD, PhD, Associate Professor, Department of Oncology, Johns Hopkins University, CRB1 4M59 1650 Orleans street, Baltimore, MD 21231, United States. fhousse1@jhmi.edu
Received: October 28, 2021
Peer-review started: October 28, 2021
First decision: December 26, 2021
Revised: January 27, 2022
Accepted: May 26, 2022
Article in press: May 26, 2022
Published online: July 7, 2022
Abstract

Dysregulated interactions between host inflammation and gut microbiota over the course of life increase the risk of colorectal cancer (CRC). While environmental factors and socio-economic realities of race remain predominant contributors to CRC disparities in African-Americans (AAs), this review focuses on the biological mediators of CRC disparity, namely the under-appreciated influence of inherited ancestral genetic regulation on mucosal innate immunity and its interaction with the microbiome. There remains a poor understanding of mechanisms linking immune-related genetic polymorphisms and microbiome diversity that could influence chronic inflammation and exacerbate CRC disparities in AAs. A better understanding of the relationship between host genetics, bacteria, and CRC pathogenesis will improve the prediction of cancer risk across race/ethnicity groups overall.

Keywords: Inflammation, African-American, Population-specific genome wide association studies, Minorities health, Microbiome, Colorectal cancer

Core Tip: Studies largely examine either variations in microbiome composition or host immunity polymorphisms, often using genome-wide association studies comprised of populations mainly of European ancestry. There is, thus, a pressing need for studies that include, recruit, and account for more widely diverse cohorts. Identification of population-associated polymorphisms driving host/microbiome interactions linked to colorectal cancer (CRC) disparity may reveal genes or pathways that could be targeted for patient-specific CRC interception strategies.