Microbiome analysis of gut microbiota in patients with colorectal polyps and healthy individuals

Colorectal polyps serve as the primary precursors for colorectal cancer. A close relationship has been observed between colorectal polyps and gut microbiota. However, the composition and role of the microbiome associated with tubular adenoma are not well understood. In this study, we prospectively evaluated alterations in gut microbiota among patients with colorectal polyps. A total of 60 subjects were enrolled in this study, including 30 patients with colorectal polyps (CP group) and 30 healthy controls (control group). The 16S rRNA sequencing was employed to characterize the gut microbiome in fecal samples. The results revealed that the beta diversity of the gut microbiota in the CP group significantly differs from that of the control group (p = 0.001). At the phylum level, the relative abundance of Bacteroides, Fusobacteria, and Proteobacteria was higher in the CP group compared to the control group (p < 0.05), whereas the relative abundance of Actinobacteria was higher in the control group in comparison to the CP group (p < 0.05). At the genus level, the abundance of Bacteroides increased in the CP group (p < 0.05), while Bifidobacterium declined in the CP group (p < 0.05). At the species level, the abundance of Clostridium perfringens, unidentified_Bacteroides, unidentified_Dorea, Escherichia coli, Clostridium ramosum, and Ruminococcus gnavus was higher (p < 0.05), whereas the abundance of Bifidobacterium adolescentis, unclassified_Bifidobacterium, Bifidobacterium longum, Faecalibacterium prausnitzii, and unidentified_Bifidobacterium is lower in CP group compared to the control group (p < 0.05). There was a structural imbalance in the composition of intestinal colonization flora for CP patients, characterized by a decrease in beneficial bacteria and an increase in harmful bacteria. Escherichia, Shigella, and Bacteroides may serve as promising biomarkers for early detection of colorectal polyps.