Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Abstract

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

“…Altering and modifying the microbiota may help treat CRC and make it easier to predict and keep track of therapy's positive and negative side effects. The gut microbiota is one of the most promising avenues for personalized CRC therapy; however, most studies are preliminary and still require clinical confirmation 141 …”

“…The gut microbiota is one of the most promising avenues for personalized CRC therapy; however, most studies are preliminary and still require clinical confirmation. 141 Certain gut microbes have been identified to play a crucial role in prognosis when using antibiotics. This effect could be due to the significant reduction in the variety and density of gut microbes caused by antibiotics.…”

Bacteria associated with glioma: a next wave in cancer treatment

“…The brain regulates the composition and behavior of gut microbiota on the one hand. On the other hand, the intestinal flora regulates the brain through several pathways, including the endocrine, immunological, neuroendocrine, and metabolic systems, constituting the “gut flora-gastrointestinal-brain axis.” ( Lyu et al., 2022 ; Pandey et al., 2023 ) Significant changes were demonstrated between mice and glioma patients regarding beta diversity, Firmicutes/Bacteroides (F/B) ratio, and expansion of the Verrucomicrobia phylum and Akkermansia genus. In a mouse model, glioma growth revoked dysbiosis of the intestines( Patrizz et al., 2020 ).…”

Major Microbiota Profile of Breast Cancer From Faecal Specimen and Cancerous Breast Tissue: A Comprehensive Systematic Review

“…For instance, Helicobacter pylori colonization is associated with gastric cancer, and increased populations of Bacteroides fragilis, Fusobacterium nucleatum, and Peptostreptococcus anaerobius play a role in colorectal cancer. In contrast, the microbiota linked with breast cancer remains heterogeneous [2,3]. Since the discovery of the microbiota population in the breast, it has been recognized that interaction between the gut and the breast microbiota contributes to the development of breast cancer.…”