A comprehensive analysis of the microbiota composition and gene expression in colorectal cancerOriginal 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 examined how gut microbiota composition and gene expression differ between colorectal cancer (CRC) tumor tissue and normal tissue. They looked for shared biological pathways linking microbial shifts to altered gene expression.
How was it studied?
The team integrated 16S rRNA gene sequencing data from 19 paired CRC and normal tissue samples with RNA sequencing data from 422 samples in The Cancer Genome Atlas. They compared microbial taxa, identified differentially expressed genes, and cross-referenced enriched pathways between the two datasets.
What did they find?
Proteobacteria and Fusobacteria increased in tumor samples while Firmicutes and Spirochaetes decreased. Fusobacterium, Catenibacterium, and Shewanella appeared only in tumor tissue, and Butyricimonas closely interacted with Clostridium in the microbiome network. Of 246 differentially expressed genes, both the microbiota shifts and the gene changes converged on bile secretion and steroid hormone biosynthesis pathways, and low expression of CYP3A4 and ABCG2 was linked to longer patient survival.
Why it matters
Linking specific microbial shifts to specific gene pathways offers candidate biomarkers, such as CYP3A4 and ABCG2, that could improve CRC diagnosis, prognosis, and treatment targeting.