Gut Dysbiosis and Post-Transplant Graft-Versus-Host Disease in Pediatric Patients

In a poster presented at the Transplantation & Cellular Therapy (TCT) 2022 Tandem Meetings from the American Society for Transplantation and Cellular Therapy and the Center for International Blood & Marrow Transplant Research, researchers reported that gut dysbiosis prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) “may predict a greater post-HSCT gut microbiota variability suggesting those with less resilient microbiota may be those who experience severe gut [graft-versus-host disease (GVHD)].”

The study, led by Ashley N. Gray, MD, MS, was undertaken to further define the association between longitudinal microbiota variability and gastrointestinal GVHD in pediatric patients undergoing allo-HSCT after a recent study found that lower microbiota diversity was associated with greater mortality in adults.

The authors collected pre- and post-HSCT stool samples from a small cohort of prospective pediatric patients undergoing allo-HSCT. Patients who developed stages 0–2 gut GVHD were stratified as a control group, while patients who experienced stages 3–4 gut GVHD at least once were stratified as the gut GVHD group. The investigators used alpha diversity and Jensen-Shannon Divergence to assess microbial characteristics between the groups.

Reportedly, “antibiotic therapy leads to acute shifts in the abundance and diversity of the gut microbiota of pediatric allo-HSCT patients.” Additionally, the authors found that “pre-HSCT gut dysbiosis may predict greater microbiota variation in bacterial diversity over time (p = 0.05).” Notably, patients who experienced gastrointestinal GVHD of stage 3–4 had significantly greater variations in their gut microbiota diversity over time compared to the control group (p = 0.007).

The data presented at TCT 2022 supported an association between gut dysbiosis and GVHD outcomes in pediatric patients that was consistent with prior research in adults. Gray and colleagues hoped that further understanding of the gastrointestinal relationships could lead to “the development of interventions and ultimately, improved clinical outcomes in this vulnerable patient population. “