Impact of a Three-Strain Lactobacilli Probiotic (BioK+) on Incidence of Hospital-Onset Clostridioides difficile: A Retrospective Observational Cohort Study

<b>Background:</b> Prevention of hospital-onset <i>Clostridioides difficile</i> infection (HO-CDI) is a priority for hospitals. In addition to standard infection control measures, some probiotics show promise in reducing HO-CDI incidence. However, prior research has produced mixed results. <b>Methods:</b> Retrospective, observational cohort study of HO-CDI incidence among inpatients treated with or without BioK+ probiotic prophylaxis. BioK+, a probiotic with three <i>Lactobacilli</i> strains, was administered to patients on antibiotics with high risk for HO-CDI. BioK+ was continued for 5 days after antibiotics were discontinued, or the patient was discharged. The primary outcome was HO-CDI incidence. <b>Results:</b> Out of 494 eligible patients on high-risk antibiotics, 343 patients received BioK+ probiotics. No cases of HO-CDI were identified in patients who received BioK+, compared to three cases among patients not on BioK+ (<i>p</i> = 0.028). In the baseline period (1 April 2021-31 March 2022) the HO-CDI incidence density was 5.62 per 10,000 bed-days. In the BioK+ probiotic period (1 April 2022-31 March 2023), the incidence density was 2.22 cases per 10,000 patient days (<i>p</i> = 0.03). <b>Conclusions:</b> When bundled with standard infection control practices, the use of BioK+ probiotics was associated with a statistically significant decreased incidence of HO-CDI among patients prescribed high-risk antibiotics.