AHR and neoplasm: This review has summarized how the gut microbiota and its metabolic products influence the formation of blood and lymphatic vessels through various signaling pathways, including the regulation of VEGF expression, modulation of inflammatory effects, interference with tumor immune responses and EMT (Epithelial-Mesenchymal Transition), the AKT signaling pathway, the Toll-like receptors (TLRs) signaling pathway, the Aryl Hydrocarbon Receptor (AHR) and Pregnane X Receptor (PXR) signaling pathways, and the Lysophosphatidic Acid (LPA) signaling pathway.