Microbiome and Immunosuppression: The Mission Study

Inclusion Criteria: * Participants undergoing kidney transplant * Male or female at least 18 years of age at time of enrollment * Will or have received a living or deceased donor kidney transplant * Planned post-transplant immunosuppression regimen of mycophenolate mofetil dosed every 12 hours (Cellcept or generic) and immediate release tacrolimus dosed twice daily with trough concentration monitoring (generic or brand formulation). * Able and willing to complete study-related procedures and visits * Signs written informed consent Exclusion Criteria: * Recipient of a previous non-kidney transplant * Subject is a multi-organ transplant recipient * Presence of active gastroparesis, and documented in the medical record * Liver dysfunction (total bilirubin \>2x upper limit of normal) within 2 months of enrollment * Patients who take medications that significantly inhibit uridine 5'-diphosphate glucuronosyltransferase (UGT) enzymes. * Patients who take medications that significantly inhibit or induce the biliary transporters * Patient is known to be HIV positive * Pregnant or nursing (lactating) women * Non-English speaking * Patients who have undergone bariatric surgery