From Inflammatory Bowel Disease to Cancer: Gut Microbiota–Immune Microenvironment Crosstalk and Natural Product‐Based Therapeutic Opportunities

Inflammatory bowel disease (IBD), primarily Crohn's disease and ulcerative colitis, is a chronic relapsing inflammatory disorder of the gastrointestinal tract and an important risk factor for IBD‐associated cancer. Increasing evidence suggests that gut microbiota dysbiosis, epithelial barrier dysfunction, and immune microenvironment remodeling jointly sustain intestinal inflammation and contribute to carcinogenesis. The gut microbiota–immune microenvironment axis has therefore emerged as a critical mechanistic link between IBD and cancer development. Here, we summarize the roles of major immune cell populations—including macrophages, T cells, B cells, neutrophils, dendritic cells, innate lymphoid cells, and natural killer cells—in mediating the crosstalk between gut microbiota and the intestinal immune microenvironment. We further highlight the potential of natural products, particularly bioactive compounds derived from traditional Chinese medicine, to target this axis in IBD and IBD‐associated cancer. Through modulation of microbial composition, inflammatory signaling, immune cell function, and epithelial barrier integrity, these agents may provide therapeutic value in prevention, treatment, and adjuvant intervention. Elucidating the mechanisms underlying this regulatory axis may offer new opportunities for precision strategies in IBD and IBD‐associated cancer.