Dysbiosis of human gut microbiome in young-onset 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?
This study examined the gut microbiome composition of patients with young-onset colorectal cancer (yCRC), a form of sporadic colorectal cancer whose incidence is rising. Researchers used 16S rRNA gene sequencing to identify microbial markers distinguishing yCRC, then validated these findings in an independent cohort. Metagenome sequencing was also performed to characterize species-level and functional differences in bacterial communities associated with yCRC.
Who was studied?
The discovery analysis drew on 728 samples analyzed by 16S rRNA gene sequencing. An independent validation cohort of 310 samples was used to confirm the identified microbial markers. A further subset of 200 samples underwent metagenome sequencing for species-level and functional analysis.
What were the most important findings?
Gut microbial diversity was increased in yCRC compared to other groups studied. Flavonifractor plautii emerged as an important bacterial species associated with yCRC, whereas the genus Streptococcus contained the key phylotype linked to old-onset colorectal cancer. Functional analysis showed that yCRC-associated bacterial communities were distinguished by a dominance of DNA binding and RNA-dependent DNA biosynthetic processes, and a random forest classifier built on these microbial features achieved strong classification performance.
What are the greatest implications of this study?
The findings suggest that gut microbiota biomarkers, particularly Flavonifractor plautii abundance and associated functional signatures, could serve as a non-invasive tool for detecting and distinguishing yCRC. This approach could help address the diagnostic gap for younger patients as sporadic colorectal cancer incidence rises in this age group. The distinct microbial and functional profile of yCRC versus old-onset colorectal cancer also points to potentially different underlying disease biology between the two age groups.