Long-Term Outcomes After CDI: FMT Versus Antibiotic-Only Treatment (LTO-CDI)

April 28, 2026 updated by: Umeå University

Long-Term Outcomes After Clostridioides Difficile Infection (CDI): Comparative Follow-Up of FMT Versus Antibiotic-Only Treatments (LTO-CDI Cohort)

The goal of this observational study is to learn about the long-term effects of fecal microbiota transplantation (FMT) compared with antibiotic-only treatment in adults who were treated for Clostridioides difficile infection (CDI) at Umeå University Hospital between 2016 and 2024. The main questions it aims to answer are:

  • Do patients treated with FMT maintain higher gut bacterial diversity up to 10 years after CDI compared with patients treated with antibiotics only?
  • Do donor gut bacteria introduced by FMT persist long-term in the recipient's gut?
  • Are there differences in gut metabolism, gut barrier function, and systemic inflammation between FMT-treated and antibiotic-only treated patients at long-term follow-up?
  • What are the long-term safety outcomes - including new diseases, hospitalizations, and mortality - in FMT-treated versus antibiotic-only treated patients?

Researchers will compare patients who received FMT to patients who received antibiotics only to see if FMT leads to lasting differences in gut microbiota, metabolism, immune markers, and clinical outcomes.

Participants will:

  • Attend a single study visit at Umeå University Hospital
  • Provide samples of blood, stool, urine, and a nasal swab
  • Complete two quality-of-life questionnaires

Clinical data will be collected from medical records for all participants.

Study Overview

Status

Not yet recruiting

Detailed Description

Study design and setting This is a single-center, long-term observational cohort study conducted at the Department of Infectious Diseases, Umeå University Hospital, Sweden. The study enrolls adult patients treated for CDI between February 1, 2016 and December 31, 2024, providing up to 10 years of follow-up from the index CDI episode. Participants are stratified into two groups: FMT-treated and antibiotic-only treated.

CDI case definition Compatible clinical presentation (≥3 loose stools in 24 hours) plus a positive nucleic acid amplification test (LAMP) for C. difficile, consistent with ESCMID diagnostic criteria.

Recruitment Potentially eligible living subjects are identified from departmental diagnosis records and contacted by mail with written study information and an opt-out form. Those who do not return the opt-out form are contacted by telephone and invited to a single study visit for informed consent and enrollment. Deceased individuals are included in safety analyses only, without contact with next of kin.

Biological sampling Blood: EDTA plasma, serum, PBMC isolation Fecal sample Urine sample Nasopharyngeal swab

Archived donor fecal samples and pre- and post-FMT patient samples from the Umeå FMT biobank will be retrieved for longitudinal comparisons.

Observational measures Gut and nasopharyngeal microbiota will be characterized by shotgun metagenomics (strain-level resolution) and 16S rRNA sequencing. Resistome profiling and detection of multidrug-resistant organisms by culture will be performed on fecal samples. Global and targeted metabolomics (short-chain fatty acids, bile acids, redox metabolites) will be performed on feces, urine, and blood. Gut barrier markers in blood will include LPS, LPS-binding protein (LBP), and EndoCAb. Systemic immune profiling will include cytokine panels, soluble immune mediators, antibodies, and transcriptomic profiling of peripheral blood mononuclear cells. The host genome will not be sequenced. Clinical observational measures will include additional CDI after index CDI. Pharmacological treatments and comorbidity at index CDI and follow-up, as well as any antibiotic exposure during follow-up will be collected from the medical records.

Study Type

Observational

Enrollment (Estimated)

250

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

      • Umeå, Sweden
        • Umea University Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients that within the study period (2016-2024) have received treatment (antibiotic-only or FMT) at Umeå University Hospital.

Description

Inclusion Criteria:

  • Adults aged 18 years or older
  • Symptomatic, microbiologically verified index CDI from February 1 2016 to December 31 2024
  • Having received CDI treatment at Umeå University Hospital (antibiotic-only or FMT)

Exclusion Criteria:

  • Age below 18 years at follow-up
  • Index CDI diagnosis not meeting ESCMID case definition
  • Testing positive for another gastrointestinal pathogen (virus/bacteria) that is more plausible to explain the clinical picture at index CDI episode
  • Declines participation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Antibiotic treatment
Participants having received antibiotic-only treatment for previous Clostridioides difficile infection.
Fecal microbiota transplantation (FMT)
Participants having received FMT for previous Clostridioides difficile infection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Intestinal microbiota diversity
Time Frame: At follow-up visit 1-10 years after baseline CDI
Intestinal microbiota diversity assessed by metagenomic sequencing of stool samples.
At follow-up visit 1-10 years after baseline CDI

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Donor gut microbiota long-term engraftment
Time Frame: At follow-up visit 1-10 years after baseline CDI
Assessment of donor gut microbiota engraftment in participants stool samples 1-10 years post FMT, performed by metagenomic sequencing.
At follow-up visit 1-10 years after baseline CDI
Stool short-chain fatty acid concentrations
Time Frame: At follow-up visit 1-10 years after baseline CDI
Stool short-chain fatty acid concentrations assessed using metabolomic methods.
At follow-up visit 1-10 years after baseline CDI
Circulating markers of intestinal barrier function
Time Frame: At follow-up visit 1-10 years after baseline CDI
Circulating biomarkers related to intestinal barrier function measured in peripheral blood.
At follow-up visit 1-10 years after baseline CDI
Health-related quality of life
Time Frame: At follow-up visit 1-10 years after baseline CDI
Patient-reported health-related quality of life assessed using the EuroQol 5-Dimension 5-Level questionnaire (EQ-5D-5L). The descriptive system comprises five dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), each with five levels (no problems to extreme problems), producing a 5-digit health state profile. Higher index values indicate better health-related quality of life.
At follow-up visit 1-10 years after baseline CDI
Number of participants with new Clostridioides difficile infection episodes after subsequent antibiotic exposure
Time Frame: Within 1-10 years after baseline CDI
Occurrence of new Clostridioides difficile infection episodes following exposure to non-CDI antibiotic treatment during follow-up.
Within 1-10 years after baseline CDI
Incidence of new comorbidities after FMT versus antibiotic-only treatment
Time Frame: From baseline CDI to 1-10 year follow-up or prior death
Incidence of new diagnoses (autoimmune, autoinflammatory, neoplastic, and metabolic conditions) in FMT-treated participants compared with antibiotic-only treated participants, ascertained from medical records using ICD-10 diagnostic codes.
From baseline CDI to 1-10 year follow-up or prior death

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Johan Rasmuson, MD, PhD, Umeå University, Department of Clinical Microbiology

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

May 1, 2026

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

May 1, 2031

Study Registration Dates

First Submitted

April 21, 2026

First Submitted That Met QC Criteria

April 28, 2026

First Posted (Actual)

May 6, 2026

Study Record Updates

Last Update Posted (Actual)

May 6, 2026

Last Update Submitted That Met QC Criteria

April 28, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared due to the sensitive nature of the clinical and biological data collected in this observational study.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Clostridioides Difficile Infection

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