A Systematic Review Evaluating the Impact of Fibre Supplementation on Gut Health and Other Clinical Outcomes in Adults with Haematological Malignancies During Haematopoietic Stem Cell Transplantation.

Background: Gut health is often disrupted in adults with haematological malignancies (HMs) receiving chemotherapy and haematopoietic stem cell transplantation (HCT). Microbial diversity is reduced, and both infection risk and inflammation increased. The role of dietary fibre in enhancing gut health, immune regulation, reducing complications, and improving clinical outcomes for people with HMs shows promise but the extent of their role remains unclear. Objectives: This systematic review evaluated the role of dietary fibre supplementation in adults with HMs undergoing HCT on gut health, immune function, and gastrointestinal health. This included assessment of differences between fibre types. Methods: A systematic search of PubMed and EMBASE was conducted following PRISMA guidelines, independently by two reviewers. Study quality was assessed using the Newcastle-Ottawa scale (NOS). Results: Of the 5023 studies after de-duplication, 63 remained after abstract and title screening, 59 studies were full-text screened, 56 studies were excluded due to language (n = 6), wrong intervention (n = 25), wrong population (n = 4), or reporting on unrelated outcomes (n = 21), and 3 studies met all inclusion criteria. Interventions included fructooligosaccharides (FOS), resistant starch (RS), and a glutamine, fibre, and oligosaccharide (GFO) prebiotic blend. Despite heterogeneity in measured outcomes, positive impacts on gut health, immune function, and gastrointestinal health were shown. Conclusions: Fibre supplementation represents a promising adjunctive strategy to improve clinical outcomes in adults with HMs undergoing HCT, by improving microbial diversity, increasing short-chain fatty acid (SCFA) production, and reducing incidence of acute GVHD. Further research is needed to establish specific recommendations for fibre in the nutritional management of patients with HM.