WMT for Multidrug-Resistant Organism UTI

This is a single-center, prospective, single-arm, exploratory clinical study to evaluate the efficacy, safety, and potential mechanisms of washed microbiota transplantation (WMT) in patients with recurrent urinary tract infections caused by multidrug-resistant organisms (MDRO-UTI). With increasing antimicrobial resistance, MDRO UTI becomes refractory and poses a significant therapeutic challenge. WMT may reconstruct gut microbiota, reduce uropathogen colonization, decrease antibiotic resistance gene burden, and modulate host immunity and metabolism. Approximately 10 eligible patients will receive WMT delivered via colonic transendoscopic enteral tubing (TET) for 3 times according to the Nanjing Consensus on Washed Microbiota Transplantation. Participants will be followed for up to 12 months with clinical, microbiological, metagenomic, metabolomic, and immunological assessments.

Inclusion Criteria: 1. Age ≥18 years, both sexes. 2. Recurrent UTI (symptomatic UTI or asymptomatic bacteriuria), with ≥2 episodes in the past 6 months or ≥3 episodes in the past year. 3. Clean-catch midstream urine culture at enrollment showing bacterial colony count ≥10\^5 CFU/ml, with multidrug-resistant organism (non-susceptible to ≥3 antimicrobial categories, including resistant and intermediate). 4. Physically eligible and willing to receive colonic TET tube placement and WMT treatment. 5. Able to provide informed consent and comply with scheduled follow-up visits and specimen collection. Exclusion Criteria: 1. Received effective antimicrobial therapy within 48 hours before WMT. 2. Unable to tolerate colonoscopy or TET tube placement. 3. Severe comorbidities with expected survival less than 6 months. 4. Pregnant or lactating women. 5. Other conditions deemed unsuitable for enrollment by the investigator.