RecruitingDietary supplementA Study of a Plant-Based Diet and Dietary Supplements in People With Smoldering Multiple Myeloma (SMM) or Monoclonal Gammopathy of Undetermined Significance (MGUS)The researchers are going this to look at how butyrate levels change in participants' stool after they are on a plant-based diet or dietary supplements (omega-3, curcumin or probiotics) for 2 weeks. All participants will have smoldering multiple myeloma (SMM) or monoclonal gammopathy of undetermined significance (MGUS). The researchers will compare how the different dietary changes affect butyrate levels in participants' stool.