Association of Fusobacterium nucleatum infection and colorectal cancer: A Mexican study

Introduction and aims: Colorectal cancer (CRC) is the third most prevalent cancer worldwide. Many risk factors are involved, and current evidence links the gut microbiota and colorectal carcinogenesis. Fusobacterium nucleatum (F. nucleatum) is proposed as one of the risk factors at the onset and during the progression of CRC, due to immune system and inflammatory modulation. Materials and methods: Ninety samples from three different regions of the colon were collected through colonoscopy in patients with CRC, and qPCR TagMan (R) was conducted to detect F. nucleatum and cytokines (IL-17, IL-23, and IL-10) in tumor, peritumor, and normal samples. The differences between them were analyzed and correlated. Results: The abundance of F. nucleatum determined through the 2(-Delta Delta Ct) method in CRC (7.750 (5.790-10.469)) was significantly higher than in the normal control (0.409 [0.251-0.817]) (p < 0.05). There was no significant association between F. nucleatum and the cytokines (p > 0.05). Conclusions: CRC is a heterogeneous disease that presents and progresses in a complex microenvironment, partially due to gut microbiome imbalance. F. nucleatum was enriched in CRC tissue, but whether that is a cause of the pathology or a consequence, has not yet been clearly defined. (C) 2021 Asociacion Mexicana de Gastroenterologia. Published by Masson Doyma Mexico S.A.