The goal of this clinical trial is to evaluate the effect of supplementing L-ornithine compared to the control group on the efficacy of Ustekinumab in patients with Crohn's disease, and to summarize the role of supplementing L-ornithine in the treatment of CD patients.

Participants will be randomized into two groups: the L-ornithine supplementation group and the control group. The patients in the L-ornithine supplementation group received oral ornithine capsules for 8 weeks. The control group did not receive additional intervention. Follow up once a week, and after the study, patients will come to the hospital to finish the evaluation indicators.

The goal of this clinical trial is to evaluate the effect of supplementing L-ornithine compared to the control group on the efficacy of Ustekinumab in patients with Crohn's disease, and to summarize the role of supplementing L-ornithine in the treatment of CD patients.

Participants will be randomized into two groups: the L-ornithine supplementation group and the control group. Patients in the L-ornithine supplementation group take oral ornithine capsules twice a day, three capsules per time, for 8 weeks, each containing 500mg of L-ornithine. The control group did not receive additional intervention. Follow up once a week, and after the study, patients will come to the hospital to finish the evaluation indicators.

Inclusion Criteria:

1. Age ≥ 18 years old, ≤ 75 years old;
2. Patients clinically diagnosed with Crohn's disease shall refer to the Chinese Guidelines for the Diagnosis and Treatment of Crohn's Disease (Guangzhou, 2023) for diagnostic criteria;
3. Patients receiving treatment with Ustekinumab;
4. Agree to participate in this study and sign an informed consent form.

Exclusion Criteria:

Participants who meet any of the following criteria are not eligible for inclusion in this study.

1. Patients with ALT or AST exceeding the normal upper limit by more than twice, and TBIL exceeding the normal upper limit by more than twice;
2. Patients with creatinine clearance rate less than 60ml/min;
3. Patients with severe active infections in the intestines or other areas that require the use of antibiotics or antiviral drugs;
4. Patients with intestinal tuberculosis, other chronic intestinal infectious diseases, and intestinal malignant tumors;
5. Pregnant and lactating women;
6. The fasting blood glucose of patients with diabetes or screening period exceeds 7.0mmol/L or glycosylated hemoglobin exceeds 6.5%;
7. Merge patients with severe mental illness, drug use, alcohol abuse, etc. who are unable to cooperate with the study;
8. Have participated in any other clinical research within the first month prior to enrollment;
9. The researcher determined that any other disease or condition is not suitable for patients participating in this study.

Some data underlying this trial cannot be shared publicly due to protection of participant's privacy.