Fusobacteria Detected in Colonoscopy Aspirates of Colon Cancer and Adenoma

Abstract

Introduction: Sequence analysis of the 16S ribosomal RNA (rRNA) gene has been widely used to identify bacterial species associated with disease. Recent studies have identified overrepresentation of Fusobacterium in colorectal cancer tissues (Genome Res 2012; 22:. 292-8, 299-306). It has also been reported that colonoscopy aspirates can be a substitute for fecal samples in analyses of the microbiota (Bioscience of Microbiota, Food and Health 2012;31:71-6). In this study, we assessed the association of the microbiota and patients with colorectal cancer or adenoma. Methods: We enrolled 26 patients with colorectal adenoma (mean age: 65.5 years), 5 patients with colorectal cancer (mean age: 63.6 years) and 5 control subjects (mean age: 51.3 years). Colon content aspirates were collected during colonoscopy. RNA was extracted from all samples, and a metagenomic analysis of the 16S rRNA gene was performed. Results: Phylum analyses revealed that Bacterotedes, Firmicutes, Proteobacteria, Actinobcteria, Spirochaetes and Fusobacteria were detected in the colonoscopy aspirates. Fusobacteria were detected 100% (31/31) in colorectal adenoma and cancer, but 40% (2/5) in the controls (p=0.014). Compared with operational taxonimc unit (OTU) proportions, Fusobacteria were detected 8-43% in patients with colorectal adenoma and 2% in patients with colon cancer and 1% in the control group. Conclusion: The colonoscopy aspirates of colorectal adenoma or cancer patients are many intestinal microbiota. Especially, Fusobacteria was detected more frequently in colorectal adenoma or cancer than in controls. These findings suggest a link between Fusobacteria in colorectal adenoma and cancer and a possible role for mucosal inflammation in this disease process.