Case Series of Bacteremia Associated with Probiotic Use in Children after Cardiac Surgery, China.

We examined probiotic-associated bacteremia in a cohort of postoperative pediatric cardiac surgery patients in China. Among 16,436 children who underwent cardiac surgery during 2019-2024, a total of 5,034 received probiotics; 6 developed bacteremia with probiotic strains (Bacillus subtilis, Bacillus licheniformis, Lacticaseibacillus rhamnosus). Three cases occurred in children who had not directly received probiotics, suggesting potential cross-contamination or catheter-related transmission. All 6 patients had complex congenital heart disease and central venous catheters; 5 underwent palliative surgery. Fever, elevated C-reactive protein and leukocytes, and use of respiratory support were common. Antibiotic therapy achieved blood-culture clearance in all; 1 death occurred because of underlying cardiac disease, not infection. Our findings conclude probiotic-associated bacteremia is rare and usually resolves with antibiotics; outcomes correlate more with cardiac complexity than bacteremia itself. Maintaining perioperative probiotic use and enhancing infection-control measures, specifically regarding central line care, are recommended to minimize the risk for probiotic-associated bacteremia in pediatric cardiosurgical patients.