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