The loss of response rate of ustekinumab(UST) is high, and the specific mechanism has not yet been elucidated. Molecular markers that can accurately predict the efficacy of UST are urgently needed to provide theoretical basis for guiding individualized treatment. Therefore, this study intends to explore the impact of intestinal epithelial fucosylation levels on the efficacy of UST in patients with Crohn's disease(CD), aiming to provide predictable molecular markers for UST to accurately treat CD.

Inclusion Criteria:

1. Diagnosed with moderate to severe Crohn's disease
2. Receiving treatment with ustekinumab
3. Received colonoscopy and collected intestinal tissue samples before and after treatment

Exclusion Criteria:

1. Pregnancy
2. Hypersensitivity to any component of ustekinumab
3. Cognitive or developmental disabilities prevent you from completing this study
4. Combined with diseases such as RA, diabetes, systemic lupus erythematosus, intestinal tuberculosis, ischemic enteritis, radiation enteritis and tumors

Inflammatory bowel disease (IBD) is a chronic inflammatory disease involving the digestive tract, including two clinical phenotypes: Crohn's disease (CD) and ulcerative colitis (UC).