title: Incidence and outcomes of bloodstream infections among hematopoietic cell transplant recipients from species commonly reported to be in over-the-counter probiotic formulations.
abstract: BACKGROUND
  Probiotic supplementation has been promoted for numerous health conditions; however, safety in immunosuppressed patients is unknown. We evaluated bloodstream infections (BSIs) caused by common probiotic organisms in hematopoietic cell transplant recipients.
  
  
  METHODS
  All blood culture (BC) results from a cohort of hematopoietic cell transplant recipients transplanted at Fred Hutchinson Cancer Research Center in Seattle, Washington, between 2002 and 2011 were reviewed. Patients with at least 1 positive BC for common probiotic organisms (Lactobacillus species, Bifidobacterium species, Streptococcus thermophilus, and Saccharomyces species) within 1 year post hematopoietic cell transplantation (HCT) were considered cases. Data were collected from center databases, which contain archived laboratory data, patient demographics, and clinical summaries.
  
  
  RESULTS
  A total of 19/3796 (0.5%) patients developed a BSI from one of these organisms within 1 year post HCT; no Bifidobacterium species or S. thermophilus were identified. Cases had a median age of 49 years (interquartile range [IQR]: 39-53), and the majority were allogeneic hematopoietic cell transplant recipients (14/19, 74%). Most positive BCs were Lactobacillus species (18/19) and occurred at a median of 84 days (IQR: 34-127) post transplant. The incidence rate of Lactobacillus bacteremia was 1.62 cases per 100,000 patient-days; the highest rate occurred within 100 days post transplant (3.3 per 100,000 patient-days). Eight patients (44%) were diagnosed with acute graft-versus-host disease of the gut prior to the development of bacteremia. No mortality was attributable to any of these infections.
  
  
  CONCLUSIONS
  Organisms frequently incorporated in available over-the-counter probiotics are infrequent causes of bacteremia after HCT. Studies evaluating the use of probiotics among high-risk patients are needed.
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.|Department of Medicine, University of Washington, Seattle, Washington, USA.
authors: S A
authors: SA
authors: Cohen
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors: M C
authors: MC
authors: Woodfield
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors: N
authors: N
authors: Boyle
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
authors: Z
authors: Z
authors: Stednick
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.|Department of Medicine, University of Washington, Seattle, Washington, USA.
authors: M
authors: M
authors: Boeckh
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington, USA. spergam@fhcrc.org.|Department of Medicine, University of Washington, Seattle, Washington, USA. spergam@fhcrc.org.|Infection Prevention, Seattle Cancer Care Alliance, Seattle, Washington, USA. spergam@fhcrc.org.
authors: S A
authors: SA
authors: Pergam
mesh_terms: D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology*; D001644:Bifidobacterium / Q000302:isolation & purification / Q000472:pathogenicity; D000071997:Blood Culture; D002648:Child; D002675:Child, Preschool; D005260:Female; D006086:Graft vs Host Disease / Q000150:complications / Q000453:epidemiology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects*; D015994:Incidence; D007778:Lactobacillus / Q000302:isolation & purification / Q000472:pathogenicity*; D008297:Male; D008875:Middle Aged; D004366:Nonprescription Drugs / Q000009:adverse effects*; D019936:Probiotics / Q000009:adverse effects* / Q000032:analysis; D012189:Retrospective Studies; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification / Q000472:pathogenicity; D048249:Streptococcus thermophilus / Q000302:isolation & purification / Q000472:pathogenicity; D066027:Transplant Recipients; D014184:Transplantation, Homologous / Q000009:adverse effects; D055815:Young Adult
chemical_list: D004366:Nonprescription Drugs
keywords: 
  Lactobacillus
  ; bacteremia; fungemia; hematopoietic cell transplant; over-the-counter; probiotic