Classification of Changes in the Fecal Microbiota Associated with Colonic Adenomatous Polyps Using a Long-Read Sequencing PlatformOriginal 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 asked whether the fecal microbiota differs in people with colonic adenomatous polyps, a common precursor to colorectal cancer. Adenomatous polyps are a recognized hallmark of colorectal carcinogenesis. Researchers profiled gut microbiota using two platforms: short-read sequencing on Illumina MiSeq and long-read sequencing on the Oxford Nanopore MinION. Long-read sequencing was used to resolve taxa at the species level, which short reads classify less reliably. Differential taxa were identified by LEfSe.
Who was studied?
The study enrolled 132 clinical subjects in Taiwan. This comprised 43 patients with polyps as the case group, 36 patients with positive immunochemical fecal occult blood tests as the OB group, and 53 healthy participants. Most case-group participants had adenomatous polyps, a minority had adenomatous plus hyperplastic polyps. All were human adults, sampled from stool. The groups did not differ in age, sex, or history of smoking or drinking.
What were the most important findings?
The long-read platform revealed significant genus-level differences in the gut microbiota of polyp patients compared with healthy subjects, whereas no such difference appeared between the occult-blood and healthy groups. Alpha diversity by the Shannon index was similar across all groups. LEfSe (LDA log10 score above 3) identified three taxa more abundant in the adenomatous polyp group and three taxa enriched in the healthy group, each representing more than 1% of the community. MeSH indexing highlights Fusobacterium, Klebsiella pneumoniae, Bacteroides, and Prevotella among the differentially abundant genera. Long-read sequencing classified over 250 genera and 700 species-level taxa, outperforming short reads for species resolution. No substantial difference in potential pathogens emerged from the short-read abundance analysis.
What are the greatest implications of this study?
The findings suggest that fecal microbial shifts, particularly at the genus level, are characteristic of adenomatous polyps and may accompany early steps toward colorectal cancer. This raises the prospect of stool-based microbial markers for early detection. The absence of differences in the occult-blood group hints that microbial signals and blood-based screening may capture different aspects of risk. The study is cross-sectional and cannot show whether microbial changes drive polyp formation or follow it, and the cohort was modest and single-center.