This study aims to evaluate whether the combination of Akkermansia muciniphila with infliximab can improve intestinal mucosal healing in patients with Crohn's disease compared with infliximab alone.

This is a prospective, randomized, controlled clinical study designed to evaluate the efficacy of Akkermansia muciniphila combined with infliximab in patients with Crohn's disease.

Eligible patients will be randomly assigned to receive either intravenous infliximab at standard clinical doses combined with Akkermansia muciniphila supplementation administered once daily or intravenous infliximab alone. The primary endpoint is complete mucosal healing at Week 26, and the secondary endpoint include endoscopic remission, endoscopic response, clinical remission and clinical response at Week 26.

Inclusion Criteria:

1. Adult patients aged 18 to 75 years.
2. Documented diagnosis of Crohn's disease established at any time prior to screening by radiological, histological, or endoscopic evidence.
3. Active Crohn's disease at screening, defined as a Crohn's Disease Activity Index (CDAI) score between 220 and 450 (inclusive).
4. Adequate cardiac, renal and hepatic function, as assessed by the investigator based on screening laboratory tests, physical examination, and medical history, without findings that would pose an undue risk for study participation.
5. Willingness and ability to provide written informed consent.
6. Agreement to undergo all scheduled study procedures, including up to 3 endoscopic evaluations.

Exclusion Criteria:

1. Use of any biologic therapy (e.g., infliximab, adalimumab, ustekinumab, vedolizumab) within 8 weeks prior to screening.
2. Use of systemic antibiotics or any probiotic preparation within 4 weeks prior to screening.
3. History of any intestinal resection or other Crohn's disease-related surgery.
4. History of or active chronic or recurrent infectious disease.
5. History of or current malignancy.
6. Pregnancy, lactation, or intention to become pregnant during the study period.