Microbiome diversity in African American, European American, and Egyptian colorectal cancer patients
Amr Elkholy, Nagavardhini Avuthu, Mohammed Abdalla, Michael Behring, Prachi Bajpai, Hyung‐Gyoon Kim, Doaa Header, Reham AH. Abo Elwafa, Hesham Saed, Amira M. Embaby, Nefertiti El-Nikhely, Sarah Obuya, Mostafa Mohamed, Ahmed Ashour Badawy, Ahmed Nawar, Farrukh Afaq, Laura Q. Rogers, Sejong Bae, James M. Shikany, Lori Brand Bateman, Mona N. Fouad, Mansoor N. Saleh, Temesgen Samuel, Sooryanarayana Varambally, Chittibabu Guda, Waleed Arafat, Upender Manne
Abstract
Purpose: Although there is an established role for microbiome dysbiosis in the pathobiology of colorectal cancer (CRC), CRC patients of various race/ethnicities demonstrate distinct clinical behaviors. Thus, we investigated microbiome dysbiosis in Egyptian, African American (AA), and European American (EA) CRC patients. Patients and methods: CRCs and their corresponding normal tissues from Egyptian (n = 17) patients of the Alexandria University Hospital, Egypt, and tissues from AA (n = 18) and EA (n = 19) patients at the University of Alabama at Birmingham were collected. DNA was isolated from frozen tissues, and the microbiome composition was analyzed by 16S rRNA sequencing. Differential microbial abundance, diversity, and metabolic pathways were identified using linear discriminant analysis (LDA) effect size analyses. Additionally, we compared these profiles with our previously published microbiome data derived from Kenyan CRC patients. Results: in CRCs of Kenyans (LDA score >4, adj. p-value <0.05). Functional analyses showed distinct microbial metabolic pathways in CRCs compared to normal tissues within the racial/ethnic groups. Egyptian CRCs, compared to normal tissues, showed lower l-methionine biosynthesis and higher galactose degradation pathways. Conclusions: Our findings showed altered mucosa-associated microbiome profiles of CRCs and their metabolic pathways across racial/ethnic groups. These findings provide a basis for future studies to link racial/ethnic microbiome differences with distinct clinical behaviors in CRC.