Changes in the bacterial profile and diversity of the gut microbiota in allogeneic hematopoietic stem cell transplant recipientsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
Researchers tracked gut microbiota changes in patients receiving allogeneic hematopoietic stem cell transplants (allo-HSCT) and asked whether those changes linked to transplant outcomes.
How was it studied?
A prospective cohort of 95 allo-HSCT recipients across three Spanish hospitals (2017 to 2021) gave stool samples before transplant and at days 14, 30, 60, and 100 after. Investigators sequenced bacterial 16S rRNA genes from 409 samples and assessed diversity and taxa abundance.
What did they find?
Alpha diversity dropped significantly at days 14, 30, and 60 versus baseline, alongside a marked decline in Blautia abundance. Patients who developed acute gastrointestinal graft-versus-host disease, bacteraemia, or who died had significantly lower Blautia levels. Comparing deceased versus surviving patients, LEfSe analysis flagged 22 differential taxa, with Enterococcus_H, Enterococcus_A, and Staphylococcus enriched in those who died.
Why it matters
The findings tie a collapse in gut diversity and Blautia loss, alongside pathogen expansion, to worse post-transplant outcomes including GVHD, bloodstream infection, and death.