Fecal Microbiota Characteristics of Patients with Colorectal Adenoma Detected by Screening: A Population-based StudyOriginal 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?
This study examined whether fecal microbiota composition differs between people with colorectal adenoma (CRA), a precancerous lesion, and those with normal colonoscopy findings. Researchers used Illumina sequencing of 16S rRNA genes amplified from DNA extracted from self-collected fecal samples preserved in RNAlater. They compared phylum-level community composition and abundance patterns between groups using regression, permutation testing, and random forest classification with leave-one-out validation. The goal was to determine if microbiota profiling could help identify CRA in a population-based screening context.
Who was studied?
The study population was fecal immunochemical test-positive (FIT+) individuals undergoing colonoscopy as part of a population-based colorectal cancer screening program. Of 95 FIT+ participants, 61 had both successful fecal microbiota profiling and colonoscopy data available for analysis. Colonoscopy findings classified these participants into 24 completely normal patients, 20 with colorectal adenoma, 2 with colorectal cancer, and 15 with other conditions.
What were the most important findings?
Phylum-level fecal community composition differed significantly between CRA and normal patients (permutation P = 0.02), and rank phylum-level abundance distinguished the two groups with an area under the curve of 0.767 (permutation P = 0.006). CRA prevalence was 59 percent in phylum-level cluster B versus 20 percent in cluster A (exact P = 0.01). Most of this difference reflected a three-fold higher median relative abundance of Proteobacteria taxa in CRA patients (Wilcoxon signed-rank P = 0.03, positive predictive value = 67 percent).
What are the greatest implications of this study?
These findings suggest that fecal microbiota profiling, particularly elevated Proteobacteria abundance, could serve as a complementary or adjunct marker for detecting colorectal adenoma in FIT-positive screening populations. Because current fecal heme testing has limited sensitivity for CRA and colonoscopy participation is low, a microbiota-based approach could help improve early, curable-stage detection. Further validation in larger cohorts would be needed to confirm whether phylum-level clustering or Proteobacteria abundance can be translated into a practical screening tool.