The Comparison of Fecal Microbiota in Left-Side and Right-Side Human Colorectal Cancer

Abstract

<b><i>Introduction:</i></b> Microbiomes play a vital role in the development and progression of cancer. The clinical status, including prognosis, genetic mutations, and sensitivity to chemotherapy, differs depending on the location of colorectal cancer (CRC); however, the association between gut microbiota and the location of CRC is not entirely understood. This study was conducted to evaluate the differences in the gut microbiota in patients with CRC according to the location of the tumor. <b><i>Methods:</i></b> Fifty-six patients who underwent surgery for CRC between August 2018 and November 2019 were included in the study. Three patients who had received neoadjuvant therapy or antibiotic treatment within 1 month before surgery were excluded. The metagenomes of microbiota in preoperative feces were assessed using the V3–V4 region of 16s rRNA amplicon sequences. <b><i>Results:</i></b> The beta diversity of the Bray-Curtis distance was significantly higher in left-sided than in right-sided CRC. <i>Fusobacterium</i> predominated in left-sided CRC according to the linear discriminant analysis effect size method. <i>Blautia</i>, Eryspelotrichales, <i>Holdemanella</i>, <i>Faecalibacterium</i>, <i>Subdoligranulum</i>, and <i>Dorea</i> constituted the dominant intestinal flora in right-sided CRC. Pathway analysis revealed that L-lysine fermentation and cob(II)yrinate a,c-diamide biosynthesis I were predominant in left-sided CRC. <b><i>Discussion:</i></b> This study demonstrated that fecal microbiota in left-sided CRC constitutionally and functionally differ from those in right-side CRC. These results will help to elucidate the biological differences according to tumor location and develop treatments for human CRC.

The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

“…In addition, Fusobacterium nucleatum is associated with tumorigenesis in colorectal cancer [16]. Furthermore, the microbiome differs in left-and right-side colorectal cancer [17,18]. The challenge of distinguishing whether certain bacteria have a selective advantage due to cancer, and are therefore more detectable in cancer patients, or whether certain bacteria promote cancer development remains unclear.…”

Characteristics of Gut Microbial Profiles of Offshore Workers and Its Associations With Diet

“…One cohort study reported that the genus Holdemanella was enriched in Tibetan Highlanders suffering from coronary artery disease compared with healthy Tibetan Highlanders and Han coronary artery disease patients living at high and low altitudes (32). Several other studies have also found that Holdemanella was significantly increased in patients suffering from autism spectrum disorder, colorectal cancer, or chronic kidney disease (33)(34)(35). The differences in the results reaffirmed the challenge of distinguishing a FIGURE 6 | Associations between microbial pathways and multiple factors.…”

Performance of the Use of Genetic Information to Assess the Risk of Colorectal Cancer in the Basque Population

“…In addition, that association had a pleiotropic effect, that is, rather than the presence of Firmicutes affecting the risk of CRC (cause and effect), there is a shared genetic component that affects both (common biologic mechanism). It has been described the importance of the microbiota in CRC risk and development [ 66 , 67 ], the differences in its composition between left and right colon cancer [ 68 , 69 , 70 ] and shared genetic variants in CRC risk and the abundance of Firmicutes [ 13 ]. Although the connection we have detected between CRC and Firmicutes is based only on their shared genetic variants, it has been observed that the involvement of Firmicutes in CRC risk was variable [ 68 , 69 , 70 , 71 ]: some genera of Firmicutes were enriched in CRC while others were depleted.…”

“…It has been described the importance of the microbiota in CRC risk and development [ 66 , 67 ], the differences in its composition between left and right colon cancer [ 68 , 69 , 70 ] and shared genetic variants in CRC risk and the abundance of Firmicutes [ 13 ]. Although the connection we have detected between CRC and Firmicutes is based only on their shared genetic variants, it has been observed that the involvement of Firmicutes in CRC risk was variable [ 68 , 69 , 70 , 71 ]: some genera of Firmicutes were enriched in CRC while others were depleted. In the case of Cyanobacteria, a higher abundance of that phylum has been observed in colorectal adenomas [ 72 ], and in animal models, it has been observed a higher abundance of Cyanobacteria when oxaliplatin is administered [ 73 ].…”