High-Fiber Diet Enhances Outcomes for Stem Cell Transplant Patients
A closer look at how dietary fiber improves survival and reduces complications like graft-versus-host disease in stem cell transplant recipients.
Topline
A high-fiber diet significantly improves survival rates and reduces the risk of acute graft-versus-host disease (aGVHD) in patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). These findings challenge the traditional low-fiber diet recommendations for these patients.
Study Details
This study, presented at the American Society of Hematology (ASH) 2024 Annual Meeting, highlights the importance of dietary fiber for allo-HCT recipients. Led by Dr. Jenny Paredes from the City of Hope National Medical Center, researchers analyzed the impact of dietary fiber on gut microbiome diversity, short-chain fatty acids like butyrate, and overall patient outcomes.
Traditional low-fiber diets aim to reduce gastrointestinal complications. However, these findings suggest that restricting fiber may inadvertently harm the gut microbiome and increase the risk of complications such as aGVHD.
Methodology
The observational study included 173 allo-HCT recipients from Memorial Sloan Kettering Cancer Center. Dietary data were collected over 3837 patient-days, covering the period from 10 days before to 30 days after transplantation. Researchers analyzed gut microbiome diversity, fecal short-chain fatty acids, and clinical outcomes.
Key Findings
Higher Microbiome Diversity: Patients with high-fiber intake showed increased microbial diversity and abundance of butyrate producers (P = .009, P = .03, respectively).
Improved Survival Rates: The high-fiber group had significantly higher overall survival rates at 24 months (P = .04).
Reduced GvHD Incidence: High-fiber diets lowered the cumulative incidence of acute gastrointestinal GvHD at day 100 (P = .034).
Additionally, preclinical mouse model studies confirmed that a fiber-rich diet enhanced gene expression associated with reduced GvHD and improved immune responses.
Implications for Practice
These findings advocate for a re-evaluation of dietary guidelines for allo-HCT patients. A moderate increase in fiber intake (10–20 grams/day) could boost microbiome diversity and reduce complications like aGVHD.
Examples of safe, fiber-rich foods include small portions of avocado, vegetable soup, or salads. Institutions are encouraged to adjust meal plans to safely incorporate these dietary changes.
However, patients with severe GvHD symptoms or conditions mimicking irritable bowel disease (IBD) may not benefit from a high-fiber diet and require tailored nutritional strategies.