A Distinct Intestinal Domination Fingerprint in Patients Undergoing Allo-HSCT: Dynamics, Predictors and Implications...

Area of Science:

• Microbiome research
• Hematopoietic stem cell transplantation
• Gastrointestinal health

Background:

• Enterococcus domination is well-studied in allogeneic hematopoietic stem cell transplantation (allo-HSCT).
• The prevalence and clinical significance of other dominant intestinal genera in allo-HSCT patients are less understood.
• Geographic variations in microbiota composition may influence outcomes.

Purpose of the Study:

• To investigate the dynamics, predictors, and clinical implications of intestinal domination in Brazilian patients undergoing allo-HSCT.
• To identify dominant bacterial genera beyond Enterococcus in this patient cohort.
• To assess the association between intestinal domination and overall survival or acute Graft-versus-Host-Disease (aGvHD).

Main Methods:

• Prospective study across four Brazilian centers.
• Longitudinal collection of fecal specimens from pre-allo-HSCT to six months post-transplantation.
• 16S rRNA gene sequencing for intestinal domination identification; logistic regression for predictor analysis.

Main Results:

• 68% of 192 fecal specimens showed intestinal domination.
• Dominant genera included Bacteroides, Akkermansia, Phascolarctobacterium, and Escherichia-Shigella.
• No significant association found between domination by these genera and overall survival or aGvHD incidence.

Conclusions:

• Brazilian allo-HSCT patients exhibit a distinct intestinal domination profile.
• No patient characteristics reliably predicted intestinal domination.
• Geographic context is crucial for interpreting microbiota-outcome associations in allo-HSCT.