Contribution of the microbiota and their secretory products to inflammation and colorectal cancer pathogenesis: the role of toll-like receptors

Abstract

Alterations in diversity and function of the gut microbiome are associated with concomitant changes in immune response, including chronic inflammation. Chronic inflammation is a major risk factor for colorectal cancer (CRC). An important component of the inflammatory response system are the toll-like receptors (TLRs). TLRs are capable of sensing microbial components, including nucleic acids, lipopolysaccharides, and peptidoglycans, as well as bacterial outer membrane vesicles (OMV). OMVs can be decorated with or carry as cargo these TLR activating factors. These microbial factors can either promote tolerance or activate signaling pathways leading to chronic inflammation. Herein we discuss the role of the microbiome and the OMVs that originate from intestinal bacteria in promoting chronic inflammation and the development of colitis-associated CRC. We also discuss the contribution of TLRs in mediating the microbiome-inflammation axis and subsequent cancer development. Understanding the role of the microbiome and its secretory factors in TLR response may lead to the development of better cancer therapeutics.

Alterations of the Gut Microbiome and Fecal Metabolome in Colorectal Cancer: Implication of Intestinal Metabolism for Tumorigenesis

“…The gut microbiome is essential for health, while dysbiosis is related to various diseases, including metabolic syndrome, diabetes, obesity, neurodegenerative disease, and cancers, including colorectal carcinogenesis ( Sheikh et al, 2021 ). A healthy gut environment is characterized by a balance of bacterial communities and their favorable metabolic action ( Nie et al, 2019 ).…”

Diet-microbiome interactions in cancer treatment: Opportunities and challenges for precision nutrition in cancer

“…, 64. , 65. Disruption of the microbiota by chronic inflammation, a risk factor for multiple cancer types, can also result in induction of pro-inflammatory pathways and select for pathogenic microbes, induce biofilm formation, or encourage the expression of virulence factors in commensal microbes.…”

Soluble peptidoglycan fragments produced by Limosilactobacillus fermentum with antiproliferative activity are suitable for potential therapeutic development: A preliminary report

“…Based on the microbiological outcomes, we further investigated the role of SPFs in an in vitro model of a human colorectal cancer HCT116 cell line. In this regard, recent scientific literature widely focuses on the anticancer properties exerted by gut microbiota against colorectal cancer ( Chen and Li, 2020 ; Sheikh et al, 2021 ). In particular, most of the clinical research between 2015 and 2017 shows the crucial role of specific gut microbiomes in postsurgical complications of colorectal cancer ( Aisu et al, 2015 ; Consoli et al, 2016 ; Theodoropoulos et al, 2016 ; Flesch et al, 2017 ; Hibberd et al, 2017 ) acting on immune system functionality and inflammation.…”