Shifts in the Fecal Microbiota Associated with Adenomatous PolypsOriginal 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 fecal microbiota of patients with adenomatous polyps, the main precursor to colorectal cancer, to patients with no polyps. Stool samples came from 233 adenoma patients and 547 non-adenoma patients across multiple US medical centers.
How was it studied?
16S rRNA gene sequencing was performed on fecal samples collected before colonoscopy and frozen within 48 hours. Differential abundance testing identified taxa distinguishing the groups, and PICRUSt was used to predict functional metabolic shifts from the 16S data.
What did they find?
Thirty-one taxa differed between groups. Bilophila, Desulfovibrio, the pro-inflammatory genus Mogibacterium, and several Bacteroidetes species were more abundant in adenoma patients. Veillonella, Clostridia, and Bifidobacteriales were more abundant in patients without adenomas. A four-genus panel (Bilophila and Mogibacterium up, others down) predicted adenoma status with an AUC of 0.66, too weak for clinical use. Adenoma-associated microbiota was predicted to have increased primary and secondary bile acid, starch, sucrose, lipid, and phenylpropanoid metabolism.
Why it matters
These shifts mirror microbiota changes already reported in colorectal cancer patients. The authors propose that a Western diet raises bile acid production, favoring bile-tolerant, hydrogen-sulfide-producing microbes like Bilophila and Desulfovibrio that may damage colonic DNA and promote adenoma-to-cancer progression.