Hematopoietic Stem Cell Transplantation Alters Age-Related Gut Microbiome Profiles
Overview
This study analyzed gut microbiome (GM) changes in pediatric and adult patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). It found that age-related differences in GM composition persist post-transplant, with distinct microbial diversity and taxonomic shifts influenced by patient age and conditioning regimens.
Background
The gut microbiome plays a critical role in clinical outcomes following allo-HSCT, including graft-versus-host disease (GvHD) and overall survival. Prior studies have linked higher microbial diversity and specific bacterial taxa with improved outcomes in adults, while pediatric data show more variability. Age influences baseline GM composition, with children typically harboring more beneficial bacteria and adults showing increased opportunistic pathogens. Understanding how HSCT affects these age-related microbial profiles is essential for optimizing patient management.
Data Highlights
Stool samples were collected before conditioning and at neutrophil engraftment from pediatric and adult allo-HSCT recipients. Microbial DNA was extracted and sequenced targeting the 16S rRNA V3–V4 region. Diversity metrics and taxonomic profiles were analyzed using standardized bioinformatics pipelines. Clinical outcomes including acute GvHD incidence and graft-versus-host disease-free, relapse-free survival (GRFS) were correlated with GM configurations. Antibiotic prophylaxis protocols were consistent across age groups.
Key Findings
Pre-transplant gut microbiome diversity differs significantly between pediatric and adult patients, reflecting age-related baseline differences.
Post-transplant microbial diversity decreases in both groups but remains distinct, indicating persistent age-related GM signatures after HSCT.
Pediatric patients more frequently receive myeloablative conditioning, leading to greater microbiome disruption compared to adults.
Specific bacterial taxa associated with beneficial outcomes, such as Blautia, show differential abundance changes post-transplant between age groups.
GM profiles correlate with clinical outcomes like acute GvHD and GRFS, with age influencing these associations.
Clinical Implications
Clinicians should consider patient age when evaluating gut microbiome changes and their impact on allo-HSCT outcomes. Tailoring conditioning regimens and microbiome-targeted interventions may improve transplant success by preserving beneficial microbial communities, especially in pediatric patients who experience greater microbiome disruption. Monitoring GM profiles could aid in risk stratification for GvHD and infection.
Conclusion
Age-related gut microbiome differences persist following allo-HSCT, influencing microbial dynamics and clinical outcomes. Integrating age-specific microbiome considerations into transplant protocols may enhance patient care and prognosis.
References
Peled et al. 2017 -- Microbiota as Predictor of Outcomes in Allogeneic Hematopoietic Stem Cell Transplantation
Taur et al. 2014 -- Intestinal Microbiota and Outcomes of Allogeneic Hematopoietic-Cell Transplantation
Shono et al. 2016 -- Increased GVHD-related Mortality with Intestinal Blautia Loss
Galloway-Peña et al. 2019 -- Pediatric Gut Microbiome and HSCT Outcomes
Montassier et al. 2016 -- Antibiotic Impact on Gut Microbiota in HSCT
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