ABSTRACT

Background: Probiotics are synthetic oral supplements containing live bacterial and fungal species hypothesized to help with various gastrointestinal conditions. However, they can cause infection if the organism spreads outside of the gastrointestinal tract. The aim of this study was to identify and describe patients who experienced systemic infections caused by probiotic use. 

Methods: This study was a retrospective chart review of pediatric and adult patients at academic medical centers who received probiotics and subsequently developed positive cultures from a sterile site for probiotic-related species. Two individuals completed the chart reviews to determine if the probiotic was the true cause of the infection. 

Results: Lactobacillus, Bifidobacterium, and Saccharomyces cultures were reviewed, with a total of 71, 8, and 2 cultures isolated from sterile sites for each organism, respectively. Further review revealed 23 Lactobacillus cultures from 13 unique patients who were taking Lactobacillus-containing probiotics. Four patients without gastrointestinal tract compromise were included in the final analysis, including 1 patient whose culture was confirmed as identical to the probiotic. Types of infections included meningitis and bacteremia. Targeted antimicrobial therapy included ampicillin, ampicillin-sulbactam, and piperacillin-tazobactam, with total durations of therapy ranging from 10 to 22 days. No patients had mortality attributed to Lactobacillus infection. 

Conclusions: Probiotics are not harmless supplements as they come with risk of serious infection as demonstrated in this review. Before use, the risks of probiotics should be considered carefully for each individual patient. Clinicians should consider avoiding probiotics in hospitalized patients, especially those with vascular or extra-ventricular access devices.