Abstract Background Nosocomial infections in patients with severe acute pancreatitis(SAP) are frequently driven by impaired intestinal barrier function, which facilitates bacterial translocation and contributes to adverse clinical outcomes. Saccharomyces boulardii can reconstitute gut microbiota composition. We investigated whether S. boulardii combined with enteral nutrition (EN) affects the microbiome and nosocomial infections in SAP. Methods This study is a single centre, open-label randomized controlled trial. We included 50 patients with SAP in a Chinese gastroenterology intensive care unit (ICU), randomized to Probiotic group (S. boulardii and EN) or the Control group (EN). Throat/oropharyngeal and rectal swabs were collected from patients with SAP on days 0, 1, 3, 6, 9, 12, and 15 of ICU admission. The primary endpoints were nosocomial infection and fungemia, whereas the secondary endpoints were ICU mortality, 28-day mortality, ICU stay, and length of hospital stay. All samples were subjected to full-length 16s rRNA and internal transcribed spacer (ITS) sequencing. Multivariate analysis was performed using normalized microbial and corresponding clinical data. Results After data processing, 213 16S rRNA and 120 ITS samples were analysed. S. boulardii prevented nosocomial infections (0/27 in the Probiotic group vs. 5/23 in the Control group; p0.05). Intestinal fungi were closely associated with nosocomial infections. Bioinformatic analysis showed that S. boulardii prevented nosocomial infections by reducing intestinal bacterial perturbation and inhibiting the proliferation of Enterococcus in the intestine, and Candida in the respiratory tract and intestines. Conclusions S. boulardii in patients with SAP may positively alter the respiratory and intestinal microbiome and decrease the incidence of nosocomial infections.
He et al. (2026) studied this question.