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)

A Randomized Placebo Controlled Study of a Plant-Based Dietary Versus Supplement Versus Placebo Intervention in Patients With Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM) - The Nutrition Prevention (NUTRIVENTION-3) Study

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 SMM
• If 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 years
• Willingness to comply with all study-related procedures
• ECOG performance status of 0-3
• Interested in learning to cook plant based recipes

Exclusion Criteria:

• Patients that already follow a whole foods plant based diet (ovo-lacto-vegetarian or processed junk food vegan diets are not excluded)
• Legume allergy
• Severe allergies such as anaphylactic shock to nuts (specifically cashews). Peanuts are not included in the meals.
• Concurrent participation in weight loss/dietary/exercise programs
• Mental impairment leading to inability to cooperate
• Enrollment onto any other therapeutic investigational study concurrently and up to 180 days prior to study start date
• Concurrent pregnancy
• Positive 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 contraindications
• Heavy drinker (defined as >2 drinks per day or >14 drinks per week)
• Current self-reported illicit drug use (eg heroin, cocaine not marijuana)
• Plan for prolonged travel during the study that would preclude adherence to prescribed diets
• History of major gastrointestinal surgery (not including appendectomy or cholecystectomy) within 3 months of enrollment
• If already taking curcumin or omega 3 supplements patients must be willing to stop it on the date of trial consent for study duration.