Mycobiome Supporting Diet to Reduce GI Toxicity Associated With ASCT

This is a non-randomized cohort study. Participants will be on a specific diet for 4 weeks prior to transplant and 10 days after transplant, and will then be asked to fill out several questionnaires during this period to see if this diet is easy and simple to follow. The questionnaires will be weekly while participants are outpatient and once admitted to the hospital, participants will need to fill it on the last day (10 days after stem cell infusion). Participants will also be requested to provide fecal swab samples which we will test for bacteria and fungi. A total of 3 samples will be taken at different time points during this study.