<p>Comparison of Gut Microbiome in Human Colorectal Cancer in Paired Tumor and Adjacent Normal Tissues</p>

Abstract

Background: To understand the biological effect of gut microbiome on the progression of colorectal cancer (CRC), we sequenced the V3-V4 region of the 16S rRNA gene to illustrate the overall structure of microbiota in the CRC patients. Methods: In this study, a total of 66 CRC patients were dichotomized into different groups based on the following characteristics: paired tumor and adjacent normal tissues, distal and proximal CRC segments, MMR (-) and MMR (+), different TNM staging and clinic tumor staging. Results: By sequencing and comparing the microbial assemblages, our results indicated that 7 microbe genus ( Fusobacterium, Faecalibacterium, Akkermansia, Ruminococcus2, Parabacteroides, Streptococcus , and f_Ruminococcaceae ) were significantly different between tumor and adjacent normal tissues; and 5 microbe genus ( Bacteroides, Fusobacterium, Faecalibacterium, Parabacteroides , and Ruminococcus2 ) were significantly different between distal and proximal CRC segments; only 2 microbe genus ( f_Enterobacteriaceae and Granulicatella ) were significantly different between MMR (-) and MMR (+); but there was no significant microbial difference were detected neither in the TNM staging nor in the clinic tumor staging. Conclusion: All these findings implied a better understanding of the alteration in the gut microbiome, which may offer new insight into diagnosing and therapying for CRC patients. Keywords: colorectal cancer, CRC, gut microbiota, 16S rRNA sequencing, TNM staging, MMR