Different Levels of Therapeutic Strategies to Recover the Microbiome to Prevent/Delay Acute Lymphoblastic Leukemia (ALL) or Arrest Its Progression in Children

Changes in the components, variety, metabolism, and products of microbiomes, particularly of the gut microbiome (GM), have been revealed to be closely associated with the onset and progression of numerous human illnesses, including hematological neoplasms. Among the latter pathologies, there is acute lymphoblastic leukemia (ALL), the most widespread malignant neoplasm in pediatric subjects. Accordingly, ALL cases present a typical dysfunctional GM during all its clinical stages and resulting inflammation, which contributes to its progression, altered response to therapy, and possible relapses. Children with ALL have GM with characteristic variations in composition, variety, and functions, and such alterations may influence and predict the complications and prognosis of ALL after chemotherapy treatment or stem cell hematopoietic transplants. In addition, growing evidence also reports the ability of GM to influence the formation, growth, and roles of the newborn's hematopoietic system through the process of developmental programming during fetal life as well as its susceptibility to the onset of onco-hematological pathologies, namely ALL. Here, we suggest some therapeutic strategies that can be applied at two levels of intervention to recover the microbiome and consequently prevent/delay ALL or arrest its progression.