Microbial metabolites in colorectal tumorigenesis and cancer therapy

Trillions of microbes are indigenous to the human gastrointestinal tract, together forming an ecological community known as the gut microbiota. The gut microbiota is involved in dietary digestion to produce various metabolites. In healthy condition, microbial metabolites have unneglectable roles in regulating host physiology and intestinal homeostasis. However, increasing studies have reported the correlation between metabolites and the development of colorectal cancer (CRC), with the identification of oncometabolites. Meanwhile, metabolites can also influence the efficacy of cancer treatments. In this review, metabolites derived from microbes-mediated metabolism of dietary carbohydrates, proteins, and cholesterol, are introduced. The roles of pro-tumorigenic (secondary bile acids and polyamines) and anti-tumorigenic (short-chain fatty acids and indole derivatives) metabolites in CRC development are then discussed. The impacts of metabolites on chemotherapy and immunotherapy are further elucidated. Collectively, given the importance of microbial metabolites in CRC, therapeutic approaches that target metabolites may be promising to improve patient outcome.

Automated summary

Trillions of microbes in the human gastrointestinal tract form an ecological community known as the gut microbiota, which plays a crucial role in dietary digestion and produces various metabolites. However, these microbial metabolites have been found to be correlated with the development of colorectal cancer (CRC) and can also impact the efficacy of cancer treatments. This review discusses the role of metabolites derived from microbes-mediated metabolism of dietary components and their influence on CRC development, as well as their impacts on chemotherapy and immunotherapy. Targeting metabolites may be a promising therapeutic approach for improving patient outcome in CRC.