Gut Microbiome Could Affect Colon Cancer Risk and Response

Researchers report that gut microbial balance is linked to colorectal cancer risk and can influence how cancers develop and respond to treatment. Experts say the microbiome can be changed by factors such as diet, physical activity, probiotics, and other interventions, though more intervention studies are needed.

Researchers and clinical experts describe a growing link between the gut microbiome and colorectal cancer. They report that microbial balance in the colon affects inflammation, the gut barrier, and immune responses over time. The microbiome is not fixed and can be influenced by everyday factors and medical interventions. Key findings: - Gut microbial imbalance (dysbiosis) is reported to promote low-level inflammation and damage to the gut lining, which researchers say can increase DNA damage in colon cells and raise cancer risk. - Several microbes have been consistently associated with colorectal cancer, including Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, Enterococcus faecalis, and some strains of E. coli; Fusobacterium is often found at higher levels in tumor tissue. - Experts note the microbiome’s activity (microbial by-products and toxins) matters as much as which bacteria are present, and that diet (especially dietary fiber and whole foods), fermented foods, probiotics, synbiotics, exercise, and procedures such as fecal microbiota transplantation are among factors reported to alter microbial balance. Summary: The reported link between the gut microbiome and colorectal cancer has implications for early detection, prevention discussions, and personalized treatment responses. Researchers emphasize that more well-designed intervention studies are needed to determine whether microbial changes drive cancer or reflect the tumor environment. Undetermined at this time.