Abstract:
Background: Alteration of gut microbiota effect on outcomes and complications in allogeneic hematopoietic stem cell transplantation (allo-HSCT). Currently, these findings are limited in Asia and have never been studied in Thailand before. We examined the patterns of changing in gut microbiota diversity and their association with complications after allo-HSCT in Thai population. Methods: We performed a pilot study. Consecutive participants age ≥ 15 years who underwent allo-HSCT in King Chulalongkorn Memorial Hospital were enrolled. We collected fecal specimens at 3 phases: within a week before the start of pre-transplant conditioning regimen, within 3 days after stem cell engraftment and finally a month after. Microbial analysis was performed by 16S rRNA gene sequencing and diversity was estimated by the Shannon diversity index. Alteration of gut microbiota diversity after transplantation and association of the gut microbiota with acute GVHD were evaluated. Results: Total of 11 participants were enrolled. 2 patients (18.2%) had an acute GVHD. No patient died during the study period. Bloodstream infection and C. difficile infection were detected in 3 patients (27.3%). The values of Shannon diversity index were significantly decreased in post-conditioning regimen group compared with other groups. These findings illustrated that the during engraftment, the bacterial richness and diversity were relatively low. Conclusions: During allo-HSCT, the diversity and stability of the gut microbiota are disrupted. The association of lower microbiota diversity with poor survival was explained in part by higher complication with acute GVHD or infection. These indicate that the gut microbiota may be an important factor in the success or failure in allo-HSCT.