A Study Comparing a Plant-Based Diet With Supplements and Placebo in People With Monoclonal Gammopathy of Undetermined Significance (MGUS) or Smoldering Multiple Myeloma (SMM)

The researchers are doing this study to look at how butyrate levels change in participants' stool after they are on a- plant-based diet for at least 12 weeks. All participants will have monoclonal gammopathy of undetermined significance (MGUS) or smoldering multiple myeloma (SMM). We will compare how the plant-based diet, omega-3 fatty acid and curcumin supplements, and placebo (an inactive substance that looks like the study supplements) affect butyrate levels in participants' stool.

Inclusion Criteria:Confirmed diagnosis of MGUS or SMMIf non light chain MGUS/SMM then M spike must be either ≥ 0.2 g/dL or BM PC ≥10% (both not required)If light chain MGUS/SMM then involved must be ≥10 mg/dL or BM PC ≥10% (both not required)If IgA MGUS/SMM then an IgA level >350 mg/dL and an abnormal immunofixation is required (M spike criteria not required).If IgD MGUS/SMM then an IgD level >50 mg/dL and an abnormal immunofixation is required (M spike criteria not required).Age ≥18 yearsWillingness to comply with all study-related proceduresECOG performance status of 0-3Interested in learning to cook plant based recipesExclusion Criteria:Patients that already follow a whole foods plant based diet (ovo-lacto-vegetarian or processed junk food vegan diets are not excluded)Legume allergySevere allergies such as anaphylactic shock to nuts (specifically cashews). Peanuts are not included in the meals.Concurrent participation in weight loss/dietary/exercise programsMental impairment leading to inability to cooperateEnrollment onto any other therapeutic investigational studyConcurrent pregnancyPositive HBV, HCV or HIV PCR test will need to be treated first and once undetectable viral load patients may enroll≥ Grade 2 electrolyte abnormalities as defined by CTCAEv5.0 (need to be resolved before enrolling on study)If in the opinion of the investigator there maybe any concerns regarding the ability of the patient to complete the study safely or any contraindicationsHeavy drinker (defined as >2 drinks per day or >14 drinks per week)Current self-reported illicit drug use (eg heroin, cocaine not marijuana)