Bridge of imbalance: How does the brain-gut axis act as a catalyst for gastrointestinal tumors in aging

Figure 4 Relationship between aging-related inflammation and gastrointestinal tumors. The occurrence of gastrointestinal tumors is closely related to gastrointestinal inflammation caused by aging. Inflammation impairs the integrity of the intestinal barrier, allowing microorganisms and metabolites to enter the bloodstream, along with oxygen free radicals that induce cellular DNA damage and mutations. Age-related decline in immune function is characterized by weakened immune function and decreased pathogen clearance. Senescent cells secrete pro-inflammatory factors, which aggravate the inflammation of the tissue microenvironment and synergize with angiogenesis to form a cancer-promoting microenvironment. The above pathological processes stimulate abnormal mucosal hyperplasia of the digestive tract and eventually lead to gastrointestinal cancer.