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

PRIMARY OBJECTIVE: I. To determine efficacy of orally-administered Lactobacillus plantarum (LBP) in preventing the development of gastrointestinal (GI) acute graft versus host disease (aGvHD) in children and adolescents undergoing alternative donor allogeneic hematopoietic cell transplantation (alloHCT). EXPLORATORY OBJECTIVES: I. To determine whether orally-administered LBP decreases the incidence of grade II-IV aGvHD following alternative donor alloHCT. II. To determine whether LBP administration maintains intestinal integrity as measured by mean serum citrulline levels and reduction in mucosal barrier injury (MBI) bacteremia. III. To measure the effects of LBP on the intestinal flora phylogenetic composition during and after alternative donor alloHCT using 16S ribosomal ribonucleic acid (rRNA) gene deep sequencing. IV. To measure effects of LBP on intestinal flora function during and after alternative donor alloHCT using metagenomic and metabolite profiling. V. To measure proposed immunomodulatory effects of LBP in mean serum levels of alloreactive-induced inflammatory cytokines (IL-2, IL-6, IL-12p70, IFN gamma, TNF alpha, etc) in patients receiving LBP compared to placebo. VI. To determine whether LBP administration reduces the incidence of Clostridium difficile-associated diarrhea in alternative donor HCT patients. VII. To determine whether LBP administration reduces hospital days within the first 120 days post hematopoietic cell transplant (HCT). VIII. To define the safety of orally administered LBP strains 299 and 299v in alternative donor HCT patients as measured by incidence of Lactobacillus plantarum bacteremia. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive Lactobacillus plantarum strains 299 and 299v orally (PO) or through nasojejunal (NJ), nasogastric (NG) or gastronomy (G) tube once daily (QD) on day 1 of transplant conditioning regimen to 56 days post alloHCT. Patients undergo alloHCT at day 0. ARM II: Patients receive placebo PO or through NJ, NG or G tube QD on day 1 of transplant conditioning regimen to 56 days post alloHCT. Patients undergo alloHCT at day 0. After completion of study treatment, patients are followed up for 120 days from alloHCT.