Gut microbiota profiles of treatment-naïve adult acute myeloid leukemia patients with neutropenic fever during intensive chemotherapy

Intestinal bacterial flora of febrile neutropenic patients had significantly diverse. However, there were scanty reports of microbiota alteration of adult patients with acute myeloid leukemia (AML). Stool samples of each treatment-naïve AML patient were collected at the day before induction chemotherapy initiation (pretreatment), first day of neutropenic fever and first day of bone marrow recovery. Bacterial DNA was extracted from stool and sequenced bacterial 16s ribosomal RNA genes by next-generation sequencing. Relative abundance, overall richness, Shannon’s diversity index and Simpson’s diversity index were calculated. Ten cases of AML patients (4 men and 6 women) were included with median age of 39 years (range: 19-49) and all of patients developed febrile neutropenia. Firmicutes were dominated over the period of neutropenic fever and subsequent declined after bone marrow recovery contrast to Bacteroidetes and Proteobacteria. Enterococcus was more abundant at febrile neutropenia period compared to pretreatment while Bacteroides and Escherichia was notably declined during the febrile neutropenia. At the operational taxonomic units (OTUs) level, there was significant higher level of overall richness of pretreatment period than febrile neutropenic episode. Both of the diversity indexes of Shannon and Simpson were considerably decreased at febrile neutropenic period. Adult AML patients with first episode of febrile neutropenia after initial intensive chemotherapy demonstrated the significant decrease of gut microbiota diversity and the level of diversity consistently remained constant despite of bone marrow recovery.