The role of microbiome in colorectal carcinogenesis and its clinical potential as a target for cancer treatment

Abstract

The role of gut microbiome-intestinal immune complex in the development of colorectal cancer and its progression is well recognized. Accordingly, certain microbial strains tend to colonize or vanish in patients with colorectal cancer. Probiotics, prebiotics, and synbiotics are expected to exhibit both anti-tumor effects and chemopreventive effects during cancer treatment through mechanisms such as xenometabolism, immune interactions, and altered eco-community. Microbial modulation can also be safely used to prevent complications during peri-operational periods of colorectal surgery. A deeper understanding of the role of intestinal microbiota as a target for colorectal cancer treatment will lead the way to a better prognosis for colorectal cancer patients.

Keywords: Colon neoplasms; Intestinal microbiome; Prebiotics; Probiotics; Synbiotics.

Fig. 1.

Step-by-step mechanisms of microbiota inducing colorectal cancer. Proposed mechanisms by which commensal gut microbiota interact with gastrointestinal epithelium and induce colorectal cancer. (A) Fusobacterium nucleatum. (B) Enterotoxigenic Bacteroides fragilis. (C) PKS + Escherichia coli. LPS, lipopolysaccharide; TLR4, Toll-like receptor 4; TIGIT, T-cell immunoglobulin and ITIM domain; CEC, colonic epithelial cell; NK cell, natural killer cell; IL, interleukin; STAT3, signal transducer and activator of transcription 3; CXCL, chemokine (C-X-C motif) ligand; CXCL1, chemokine (C-X-C motif) ligand 1 peptide; APC, adenomatosis polyposis coli; PKS, polyketide synthase.