Lactobacillus Plantarum in Preventing Acute Graft Versus Host Disease in Children Undergoing Donor Stem Cell Transplant

Inclusion Criteria:

All clinical and laboratory studies, if applicable, must be obtained within 21 days prior to start of protocol therapy (repeat if necessary); protocol therapy must begin within 6 months of study enrollment
Patient must have a diagnosis that is managed with an alternative donor allogeneic hematopoietic cell transplant
Patients must have a Lansky (for patients =< 16 years of age) or Karnofsky (for patients > 16 years of age) performance status score of >= 70; patients who are unable to walk because of a chronic underlying condition (such as paralysis), but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing performance score

Hematopoietic cell transplant (HCT)

Patient must be receiving cells from alternative donor defined as one of the following:

Unrelated donor with a complete human leukocyte antigen (HLA) match or a 1 or 2 HLA mismatch, considering only HLA-A, HLA-B, HLA-C, and HLA-DRB1
Related donor with a 1 or more HLA mismatch (including haplo-identical)
Note: History of HCT or other cellular therapy (e.g. chimeric antigen receptor [CAR]-T cells, donor lymphocyte infusions) is permitted

Exclusion Criteria:

Patient plans on receiving stem cells from a matched (8/8) related donor
Patient has used a probiotic dietary supplement within the previous 30 days of enrollment; (consumption of yogurt products is allowed)
Patient has a history of severe GI tract insult including but not limited to previous bowel perforation, grade 4 neutropenic colitis or typhlitis, inflammatory bowel syndrome, short small bowel syndrome (Crohn's disease, ulcerative colitis), history of gastrointestinal GVHD, or history of bowel resection
Patient has a medical, psychiatric or social issue that would compromise patient safety or compliance with protocol therapy, or interfere with consent, study participation, follow up, or interpretation of study results
Female patients who are pregnant are not eligible; women of childbearing potential require a negative pregnancy test prior to enrollment
Patient has diarrhea at the time of enrollment which is Clostridium difficile toxin positive
Patient is receiving antibiotic therapy for an active bacterial infection
Patient is allergic to all third or fourth generation cephalosporins, carbapenems, and all aminoglycosides, which are used to empirically treat LBP bacteremia