Study Using Prebiotics to Improve Gut Microbiome Diversity After Autologous Stem Cell Transplantation

Higher gut microbiome diversity has been associated with improved survival following autologous stem cell transplantation in multiple myeloma and lymphoma, but no strategies have been identified to date that specifically target the gut microbiome. The investigators hypothesize that prebiotic supplementation with resistant starch (RS) will improve gut microbiome diversity at time of stem cell engraftment.

To test this hypothesis, the study will be a randomized, double-blind, placebo-controlled trial of resistant starch versus placebo (maltodextrin) in participants with myeloma or lymphoma undergoing autologous stem cell transplantation. Thirty subjects will be randomized 1:1 to the RS or placebo arm, dosed at 20g daily for 3 days followed by an increased to 20g twice a day mixed into a food item of the participant's choice. The intervention will begin approximately 10 days prior to stem cell infusion and will continue until the first day of neutrophil engraftment (first day absolute neutrophil count >500) or approximately 30 days in total. Fecal samples will be collected at 4 timepoints for microbiome analysis: 1) at study enrollment 2) day of stem cell infusion 3) day +7 post auto transplant and 4) first day of engraftment defined as absolute neutrophil count >500 (approximately 10-14 days post-transplant).

The primary endpoint will be the difference in gut microbiome diversity between the RS and placebo arm collected at the engraftment timepoint. Secondary endpoints will include dietary evaluation to assess the impact of subject diet on microbiome response to intervention and serum sample collection to assess differences to gut permeability during transplant.