Intestinal microbiota as a predictor of the development of systemic blood flow infections in hematological cancer patients with autologous hematopoietic stem cell transplantation: data from the real-life clinical practice

It is known that qualitative and quantitative changes in the intestinal microbiota play an important role as predictors of the development of systemic bloodstream infections in allogeneic hematopoietic stem cell transplantation (HSCT). The role of the intestinal microbiota in autologous HSCT is much less studied. It has now been shown that endogenous infection from the intestine plays a leading role in the development of Gramnegative bloodstream infections. It has been established that the dominance of the Proteobacteria type in the spectrum of the intestinal microbiome is an independent factor in the development of gram-negative bloodstream infections in oncohematological patients with allogeneic HSCT. The aim of our work was to study the characteristics of the intestinal microbiome that contribute to the development of infections in oncohematological patients during high-dose chemotherapy with autologous HSCT in real clinical practice. We conducted a study to monitoring in real clinical conditions the diversity of the gut microbiome during autologous HSCT. Nine patients with multiple myeloma and follicular lymphoma were studied. The protocol included the collection of stool samples before the start of autologous HSCT and in the post-transplant period. Decreased gut microbiome biodiversity has been shown to be an important predictor of infections in HSCT. Our studies have shown that a significant (p=0.0215) decrease in the diversity index is also observed in autologous HSCT. The dominance of the Proteobacteria type in the spectrum of the intestinal microbiome is an independent factor in the development of gram-negative bloodstream infections. In general, monitoring of the biodiversity of the intestinal microbiome can be used in real clinical conditions in both allogeneic and autologous HSCT to identify highrisk groups for developing bloodstream infections. When monitoring microbiome composition, samples should be assessed both before and after HSCT.