Abstract
Background & Aims:
Gut microbiota is closely related to the occurrence and development of colorectal cancer (CRC). However, the differences of bacterial co-abundance groups (CAGs) between tumor tissue (TT) and adjacent normal tissue (NT), as well as their associations with clinical features, were need to be clarified.
Methods
Bacterial 16S rRNA sequencing was performed by using TT samples and NT samples of 251 patients with colorectal cancer. Microbial diversity, taxonomic characteristics, microbial composition, and functional pathways were compared between TT and NT. Hierarchical clustering was used to construct CAGs.
Results
Four CAGs were grouped in the hierarchical cluster analysis. CAG 2, which was mainly comprised of pathogenic bacteria, was significantly enriched in TT samples (2.27% in TT vs. 0.78% in NT, p < 0.0001). While CAG 4, which was mainly comprised of non-pathogenic bacteria, was significantly enriched in NT samples (0.62% in TT vs. 0.79% in NT, p = 0.0004). In addition, CAG 2 was also significantly associated with tumor microsatellite status (13.2% in unstable vs. 2.0% in stable, p = 0.016) and CAG 4 was positively correlated with the level of CA199 (r = 0.17, p = 0.009).
Conclusions
our research will deepen our understanding of the interactions among multiple bacteria and offer insights into the potential mechanism of NT to TT transition.