Microbiome diversity in African American, European American, and Egyptian colorectal cancer patientsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers compared the tumor and adjacent normal-tissue microbiomes of colorectal cancer (CRC) patients from three populations: Egyptian (n=17), African American (n=18), and European American (n=19). They also compared results to previously published Kenyan CRC microbiome data.
How was it studied?
DNA from frozen CRC and matched normal tissue was sequenced using 16S rRNA gene sequencing. Differential microbial abundance, diversity, and predicted metabolic pathways were analyzed with linear discriminant analysis (LDA) effect size methods.
What did they find?
Each racial and ethnic group showed a distinct dysbiosis signature in CRC tissue (LDA score above 4, adjusted p under 0.05). Egyptian tumors were enriched in Herbaspirillum and Staphylococcus, African American tumors in Leptotrichia, European American tumors in Flexspiria and Streptococcus, and Kenyan tumors in Akkermansia muciniphila and Prevotella nigrescens. Egyptian CRC tissue also showed lower l-methionine biosynthesis and higher galactose degradation pathway activity compared to normal tissue.
Why it matters
The findings suggest CRC-associated microbiome dysbiosis is not uniform across populations, which may help explain race and ethnicity-linked differences in CRC clinical behavior. The authors frame this as a basis for future studies linking microbiome differences to clinical outcomes.