The goal of this clinical trial is to learn if FT1 is safe and works to treat short bowel syndrome (SBS) in adults. It will also learn about the PK/PD profile of FT1.

Researchers will compare FT1 to a placebo (a look-alike substance that contains no drug) to see if FT1 is safe and effective in patients with SBS.

Participants will

• Receive multiple injections of FT1 or placebo according to weight.
• Visit the clinic for assessment.

In this placebo-controlled, double-blind, randomized, crossover phase 2 trial, 8 adult SBS patients are treated with once-weekly FT1 or placebo (1:1) for 5 weeks, followed by a washout period of at least 6 weeks, and then the alternate treatment for a further 5 weeks.

Efficacy is evaluated through a 72 hour metabolic balance study conducted at baseline and at the end of each treatment cycle.

Inclusion Criteria:

• Age ≥ 18 years, male or female.
• SBS secondary to surgical resection of the small intestine, screened for at least 12 months after pre intestinal resection surgery;
• Stable weight before screening; For patients requiring parenteral support (PS), PS volume remained stable (with changes in volume or energy content<25%) within 14 days prior to randomization;
• Willing to undergo colonoscopy and remove polyps assessed by researchers to be at risk of cancer;
• During the trial period, there were no plans to perform any major abdominal surgeries (such as intestinal resection exceeding 10% or surgeries that alter intestinal anatomy, such as stoma surgery);
• During the baseline metabolic balance study, the average daily fecal wet rearrangement amount was ≥ 800g;

Exclusion Criteria:

• Having undergone major abdominal surgery (such as intestinal resection exceeding 10%) within the past 6 months prior to screening;
• History of clinically significant intestinal adhesions and/or chronic abdominal pain;
• History of persistent radiation enteritis, celiac disease, refractory diarrhea, etc;
• Patients with malignant tumors within the past 5 years (excluding fully treated cervical carcinoma in situ, basal cell or squamous cell carcinoma of the skin, local prostate cancer after radical surgery, and ductal carcinoma in situ of the breast after radical surgery);
• History of gallstones in the past 3 years, except for those who have undergone cholecystectomy for gallstones; Acute cholecystitis or biliary obstruction related diseases that have not been treated within the previous month or during the screening period;
• IBD patients with active inflammatory bowel disease (IBD), or requiring increased or altered immunosuppressive therapy in the past 3 months, or receiving biologic therapy in the past 6 months;
• Occurrence of central venous catheter-related bloodstream infections within 2 months prior to and during the screening period;
• Patients diagnosed with decompensated heart failure (NYHA grade III or above) and/or unstable angina and/or myocardial infarction from 6 months prior to screening until the first administration of the study drug;
• Screening for individuals with rectal bleeding within the first 3 months;
• Individuals with absorption instability caused by cystic fibrosis, untreated megacolon disease, or known DNA abnormalities (such as familial adenomatous polyposis, Fanconi syndrome);
• Serious active, uncontrolled, untreated, acute onset systemic diseases (such as cardiovascular, respiratory, renal, infectious, endocrine, liver or central nervous system, etc.);
• Pregnant or breastfeeding women.
• The investigator believes the subject is unsuitable for participating in this clinical study.