Dr Paredes on the Association Between Fiber Intake and Improved Survival With Reduced GI aGVHD After Allo-HCT

"We hypothesized that having a dietary intervention [would] help with overall survival [OS]. We are here for to try to improve survival of our patients, and we were very pleased to see that, in fact, people who had a higher consumption of fiber had better OS."

Jenny Paredes, PhD, a research scientist studying post-transplant outcomes at City of Hope, discussed the association between dietary fiber intake and overall survival (OS) and gastrointestinal acute graft-vs-host disease (GI aGVHD) in recipients of allogeneic hematopoietic cell transplantation (allo-HCT).

Paredes and colleagues conducted an observational study evaluating whether increased dietary fiber intake could improve post-transplant outcomes. The investigation was based on the hypothesis that dietary modulation, particularly through fiber, might support a healthier gut microbiome, which plays a central role in immune homeostasis following allo-HCT. The results demonstrated a positive association between higher fiber consumption and improved OS at 24 months.

Importantly, patients with increased fiber intake also experienced a reduced incidence of lower GI aGVHD, Paredes noted. Lower GI aGVHD represents a particularly severe and treatment-refractory form of the disease, often leading to significant morbidity and mortality. The observed reduction in cumulative incidence supports a potential protective role of fiber, likely mediated through alterations in the gut microbiome and inflammatory signaling pathways, she added.

Preclinical models of GVHD have further corroborated these findings, showing that dietary fiber influences immune responses and may mitigate inflammatory complications. These data, although preliminary, provide a compelling rationale for integrating nutritional interventions into comprehensive GVHD management strategies, Paredes emphasized.

Despite these promising outcomes, the mechanisms underlying the observed associations remain to be fully elucidated, Paredes continued. Ongoing and future research will focus on determining whether specific types of fiber are more beneficial, how microbial composition and function change in response to fiber, and whether long-term outcomes are maintained beyond the initial 24-month follow-up.