Xylitol BSI Multisite - Reduction of Bloodstream Infections From Oral Organisms in Pediatric Stem Cell Transplant

Inclusion Criteria: * Provide signed and dated informed consent and assent (when applicable) form * Willing to comply with all study procedures and be available for the duration of the study * Admitted and planning to undergo an allogeneic stem cell transplant (SCT) at Cincinnati Children's Hospital Medical Center (CCHMC), Boston Children's Hospital, or Children's Hospital of Colorado (Denver). * Male or female, 4 months to 25 years of age at the time of SCT (Day 0) * Have a minimum of one tooth * Agree to avoid chewing gum and toothpaste that contains xylitol during the intervention period Exclusion Criteria: * Prior radiation treatment for cancer of the oral cavity, head, or neck in the past 6 months per the study participant's medical record * Cranial boost in patients receiving total body irradiation * Known history of allergy to xylitol * Known history of allergy to grapes or grape flavoring * Undergoing a conditioning-free allogeneic stem cell transplant (patient does not receive any chemotherapy or radiation prior to stem cell infusion)