APLN and neoplasm: Identified 5576 active bacterial species and 381 archaeal species in EC patients. Key species and pathways (e.g., Apelin, Wnt, IL-17) linked to tumor migration and host-microbiota metabolic crosstalk. Microbes potentially influence EMT and unfolded protein response. Among the most abundant species in the EC group: Clostridium botulinum, Mycoplasma hyopneumoniae, Bacillus cereus, Pasteurella multocida. 17 species showed significant differences between EC group and control group (e.g., Borrelia coriaceae ↑ in EC; Streptococcus mitis ↓ in EC.