Dr van den Brink on a High-Fiber Dietary Intervention in Smoldering Multiple Myeloma

Marcel van den Brink, MD, PhD, director, the Division of Hematologic Malignancies, City of Hope, discusses findings from the NUTRIVENTION3 trial (NCT05640843) evaluating a high-fiber dietary intervention designed to assess its impact on precursor plasma cell disorders, including monoclonal gammopathy of uncertain significance and smoldering multiple myeloma.

The single-arm trial assessed whether a plant-based, high-fiber diet over several months could influence disease biomarkers and delay progression in 20 patients with early-stage plasma cell disorders, van den Brink begins. These conditions, which are asymptomatic, represent a spectrum of disease states with varying risks of progression to multiple myeloma, he explains.

Results from NUTRIVENTION3 showed that this dietary intervention was safe, feasible, improved quality of life, and mitigated modifiable risk factors. It also improved biomarkers of disease and delayed progression in 2 patients, van den Brink notes. Additional health improvements included reduced body weight and enhanced energy levels. Notably, many participants continued adhering to a high-fiber diet post-trial, experiencing sustained benefits, van den Brink explains.

In addition, the trial focused on the diet’s impact on the gut microbiome, van den Brink continues. Fiber, which is metabolized by gut bacteria, promoted the growth of commensal anaerobes, beneficial bacteria that produce short-chain fatty acids (SCFAs), he details. SCFAs have been shown to exert immunomodulatory effects and impact plasma cell activity, potentially influencing disease progression, van den Brink notes.

Findings from the trial were corroborated by preclinical mouse models, in which the dietary intervention was associated with reduced plasma cell activity, including suppression of targeted myeloma cells, van den Brink says. These results suggest that dietary modification may serve as a novel, non-pharmacologic strategy to manage early-stage plasma cell disorders.

Although clinical benefit was most evident in a subset of patients, the trial highlights the potential of nutritional interventions to modulate disease biology through gut microbiota-derived metabolites, van den Brink emphasizes. This approach could complement existing strategies for managing precursor plasma cell disorders, particularly in intermediate-risk populations, he adds.

Further research in larger cohorts is needed to validate these findings and better understand the role of diet-microbiome interactions in plasma cell biology, van den Brink concludes.