[Evaluation of the efficacy and safety of multi-center fecal microbiota transplantation for treatment of functional constipation: A retrospective real-world study].

<b>Objective:</b> To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) for treating functional constipation, analyze the incidence of, and factors that influence, adverse events, and provide scientific evidence for optimizing FMT treatment. <b>Methods:</b> This retrospective, multicenter, single-arm, pre-post real-world study included 1529 patients with functional constipation from four clinical centers. Eligibility criteria comprised meeting the diagnostic criteria for functional constipation, having undergone at least one FMT treatment, complete pre- and post-treatment data available, and age ≥18 years. Patients who had received other interventions affecting gut function within 1 month before treatment and those with severe organic diseases or immune deficiencies were excluded. Applying the above criteria yielded 1529 eligible patients with functional constipation from four medical centers (1405 from the Shanghai Tenth People's Hospital Affiliated to Tongji University, 20 from the Central Hospital of Wuhan, 67 from the Shanxi Bethune Hospital and 37 from the Longgang District People's Hospital of Shenzhen). The study cohort comprised 746 male (48.8%) and 783 female patients (51.2%) of mean age (51.4 ± 17.4) years, mean body mass index (26.4 ± 4.9) kg/m², and mean duration of disease (15.0 ± 8.3) years. The primary outcomes were the incidence, types, and severity of adverse reactions during treatment, and their impact on patients' quality of life. Secondary outcomes included: (1) the efficacy of FMT in treating constipation. This was assessed based on changes in Patient Assessment of Constipation Symptoms (PAC-SYM) scores, where higher score indicates worse symptom. (2) Subjective satisfaction, evaluated through questionnaires or rating scales, reflecting patients' acceptance of and satisfaction with the treatment, with scores ranging from 1 to 5, where higher scores indicated greater satisfaction. Paired t-tests and Wilcoxon signed-rank tests were used to evaluate changes in symptom scores and biochemical indicators before and after treatment. Logistic regression was performed to analyze factors influencing adverse events, and subgroup analyses to explored differences in efficacy between patient groups. <b>Results:</b> In this cohort of 1529 patients with functional constipation, adverse reactions were primarily mild to moderate (1048/1529,68.5%). They comprised fever in 54 patients (3.5%), dizziness or fatigue in 218 (14.3%), throat discomfort in 806 (52.7%), nausea and vomiting in 166 (10.9%), and abdominal distension or pain in 415 (27.1%). According to multivariate logistic regression analysis, PAC-SYM scores were associated with the rate of adverse reactions, higher scores indicating a lower risk (OR = 0.958, 95% CI: 0.923-0.993, <i>P</i>=0.021). Among the 1529 patients, 274 (17.9%) underwent two or more treatment courses. After one treatment course, the patients' PAC-SYM scores decreased from (37.7 ± 3.2) pre-treatment to (23.7 ± 8.6) (mean difference 14.0 ± 9.1). PAC-SYM scores decreased by (20.7 ± 7.7) after two courses of FMT, and by (19.4 ± 6.3) after three courses. After treatment, 50.7%(775/1529) of patients reported satisfaction scores of ≥4. Adverse reactions impacted satisfaction; specifically, dizziness/fatigue, throat discomfort, and abdominal distension/pain were significantly associated with satisfaction (all <i>P</i> < 0.05). <b>Conclusions:</b> FMT achieved good relief of symptoms of functional constipation and multiple treatment courses have a cumulative effect. Adverse reactions, mainly dizziness/fatigue, throat discomfort, and abdominal distension/pain, had significant negative impacts on patient satisfaction.