TY - JOUR
T1 - Network Analysis of Gut Microbiota Including Fusobacterium and Oral Origin Bacteria and Their Distribution on Tumor Surface, Normal Mucosa, and in Feces in Patients with Colorectal Cancer
AU - Ohashi, Ayako
AU - Yamamura, Takeshi
AU - Nakamura, Masanao
AU - Maeda, Keiko
AU - Sawada, Tsunaki
AU - Ishikawa, Eri
AU - Yamamoto, Kenta
AU - Ishikawa, Takuya
AU - Kakushima, Naomi
AU - Furukawa, Kazuhiro
AU - Ohno, Eizaburo
AU - Honda, Takashi
AU - Kawashima, Hiroki
AU - Ishigami, Masatoshi
AU - Fujishiro, Mitsuhiro
N1 - Publisher Copyright:
© 2022
PY - 2022/12/1
Y1 - 2022/12/1
N2 - Introduction: Fusobacterium and several bacteria are reported to be associated with colorectal cancer (CRC). However, their relationship and whether they cause CRC or are just adapted to the cancerous environment is not known. We approached this subject by investigating the correlation and distribution of the bacteria throughout the colon in patients with CRC and elucidated the relationship between microbiota and CRC. Methods: Twenty-five patients with CRC who underwent colonoscopy for endoscopic submucosal dissection or surgery were prospectively enrolled. Fecal samples were taken before bowel preparation, and mucosal samples were collected from three sites (tumor surface, tumor-adjacent mucosa, and cecum) during colonoscopy using a cytology brush. The microbiota was identified and analyzed by sequencing of the 16S rRNA gene of the V3-V4 region. We evaluated the correlation between the bacteria based on network analysis and the distribution of Fusobacterium in the colon. Results: A network consisting of many bacteria was found in all sites; especially, oral origin bacteria including Fusobacterium formed a positively correlated network on tumor surface. Streptococcus showed a significantly higher relative abundance on tumor surface than in feces. The relative abundance of Fusobacterium had significant positive correlations between tumor surface and feces, tumor-adjacent mucosa, and cecum. Conclusion: In patients with CRC, many bacteria were correlated with each other, and Fusobacterium and oral origin bacteria formed a positively correlated network on tumor surface. Fusobacterium was equally distributed on tumor surface and throughout the lumen and mucus in the colon. In the colon where Fusobacterium is widely distributed, Fusobacterium would adhere to the tumor surface and be correlated with oral origin bacteria to make a microenvironment that is favorable for CRC.
AB - Introduction: Fusobacterium and several bacteria are reported to be associated with colorectal cancer (CRC). However, their relationship and whether they cause CRC or are just adapted to the cancerous environment is not known. We approached this subject by investigating the correlation and distribution of the bacteria throughout the colon in patients with CRC and elucidated the relationship between microbiota and CRC. Methods: Twenty-five patients with CRC who underwent colonoscopy for endoscopic submucosal dissection or surgery were prospectively enrolled. Fecal samples were taken before bowel preparation, and mucosal samples were collected from three sites (tumor surface, tumor-adjacent mucosa, and cecum) during colonoscopy using a cytology brush. The microbiota was identified and analyzed by sequencing of the 16S rRNA gene of the V3-V4 region. We evaluated the correlation between the bacteria based on network analysis and the distribution of Fusobacterium in the colon. Results: A network consisting of many bacteria was found in all sites; especially, oral origin bacteria including Fusobacterium formed a positively correlated network on tumor surface. Streptococcus showed a significantly higher relative abundance on tumor surface than in feces. The relative abundance of Fusobacterium had significant positive correlations between tumor surface and feces, tumor-adjacent mucosa, and cecum. Conclusion: In patients with CRC, many bacteria were correlated with each other, and Fusobacterium and oral origin bacteria formed a positively correlated network on tumor surface. Fusobacterium was equally distributed on tumor surface and throughout the lumen and mucus in the colon. In the colon where Fusobacterium is widely distributed, Fusobacterium would adhere to the tumor surface and be correlated with oral origin bacteria to make a microenvironment that is favorable for CRC.
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U2 - 10.1159/000527170
DO - 10.1159/000527170
M3 - Article
C2 - 36349755
AN - SCOPUS:85143380189
SN - 0012-2823
VL - 103
SP - 451
EP - 461
JO - Digestion
JF - Digestion
IS - 6
ER -