Gut microbiome alterations at acute myeloid leukemia diagnosis are associated with muscle weakness and anorexia.

The gut microbiota makes critical contributions to host homeostasis, and its role in the treatment of acute myeloid leukemia (AML) has attracted attention. We investigated whether the gut microbiome is affected by AML, and whether such changes are associated with hallmarks of cachexia. Biological samples and clinical data were collected from 30 antibiotic- free AML patients at diagnosis and matched volunteers (1:1) in a multicenter, cross-sectional, prospective study. The composition and functional potential of the fecal microbiota were analyzed using shotgun metagenomics. Fecal, blood, and urinary metabolomics analyses were performed. AML patients displayed muscle weakness, anorexia, signs of altered gut function, and glycemic disorders. The composition of the fecal microbiota differed between patients with AML and control subjects, with an increase in oral bacteria. Alterations in bacterial functions and fecal metabolome support an altered redox status in the gut microbiota, which may contribute to the altered redox status observed in patients with AML. Eubacterium eligens, reduced 3-fold in AML patients, was strongly correlated with muscle strength and citrulline, a marker of enterocyte mass and function. Blautia and Parabacteroides, increased in patients with AML, were correlated with anorexia. Several bacterial taxa and metabolites (e.g., Blautia, Prevotella, phenylacetate, and hippurate) previously associated with glycemic disorders were altered. Our work revealed important perturbations in the gut microbiome of AML patients at diagnosis, which are associated with muscle strength, altered redox status, and anorexia. These findings pave the way for future mechanistic work to explore the function and therapeutic potential of the bacteria identified in this study.

Gut microbiota alterations induced by intensive chemotherapy in acute myeloid leukaemia patients are associated with gut barrier dysfunction and body weight loss.

BACKGROUND & AIMS: Acute myeloid leukaemia (AML) chemotherapy has been reported to impact gut microbiota composition. In this study, we investigated using a multi -omics strategy the changes in the gut microbiome induced by AML intense therapy and their association with gut barrier function and cachectic hallmarks. METHODS: 10 AML patients, allocated to standard induction chemotherapy (SIC), were recruited. Samples and data were collected before any therapeutic intervention (T0), at the end of the SIC (T1) and at discharge (T4). Gut microbiota composition and function, markers of inflammation, metabolism, gut barrier function and cachexia, as well as faecal, blood and urine metabolomes were assessed. RESULTS: AML patients demonstrated decreased appetite, weight loss and muscle wasting during hospitalization, with an incidence of cachexia of 50%. AML intensive treatment transiently impaired the gut barrier function and led to a long-lasting change of gut microbiota composition characterized by an important loss of diversity. Lactobacillaceae and Campylobacter concisus were increased at T1 while Enterococcus faecium and Staphylococcus were increased at T4. Metabolomics analyses revealed a reduction in urinary hippurate and faecal bacterial amino acid metabolites (bAAm) (2-methylbutyrate, isovalerate, phenylacetate). Integration using DIABLO revealed a deep interconnection between all the datasets. Importantly, we identified bacteria which disappearance was associated with impaired gut barrier function (Odoribacter splanchnicus) and body weight loss (Gemmiger formicilis), suggesting these bacteria as actionable targets. CONCLUSION: AML intensive therapy transiently impairs the gut barrier function while inducing enduring alterations in the composition and metabolic activity of the gut microbiota that associate with body weight loss. TRIAL REGISTRATION: NCT03881826, https://clinicaltrials.gov/ct2/show/NCT03881826.