# Risk Factors for Antibiotic Exposure Post–Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection: A Prospective Multicenter Observational Study

## TL;DR

This study identifies risk factors for antibiotic use after fecal microbiota transplantation, which can increase the chance of recurring C. difficile infection.

## Contribution

The study prospectively identifies specific risk factors for non-CDI antibiotic use after FMT in patients with recurrent CDI.

## Key findings

- Immunocompromised status increases the odds of antibiotic use after FMT.
- Patients with more than three prior non-CDI antibiotic courses are at higher risk.
- Hospitalization for CDI before FMT is linked to increased post-FMT antibiotic use.

## Abstract

Recurrent Clostridioides difficile infection (CDI) is primarily driven by antibiotic-induced disruption of the indigenous intestinal microbiota. Restoration of microbiota through fecal microbiota transplantation (FMT) is effective in preventing subsequent CDI, although this effect is attenuated with additional antibiotic exposure. The aim of this study was to identify the risk factors for recurrent antibiotic administration after FMT.

This is a prospective cohort of patients who were administered FMT for recurrent CDI from 1 July 2019 through 23 November 2023 across 6 institutions in the United States. Providers collected de-identified data at the time of FMT administration and in the months post–FMT administration.

The analysis included 448 patients. Risk factors for non-CDI antibiotic administration within 2 months of FMT included immunocompromised status (odds ratio [OR], 2.2 [95% confidence interval {CI}, 1.1–4.4]; P = .02), >3 non-CDI antibiotic courses pre-FMT (OR, 3.1 [95% CI, 1.4–6.8]; P = .006), and prior hospitalization for CDI (OR, 2.0 [95% CI, 1.1–3.8]; P = .02). The most common indications for non-CDI antibiotic administration post-FMT were urinary tract infections, respiratory infections, and procedure prophylaxis.

Non-CDI antibiotic exposure significantly increases the risk of CDI recurrence post-FMT. Risk factors for non-CDI antibiotic administration within 2 months of FMT include immunocompromised status, multiple prior non-CDI antibiotics, and prior hospitalization for CDI. These individuals may benefit from additional or modified recurrent CDI prevention strategies.