Gut-Microbiota-Immune-Brain Axis and Brain Glioma: A Well-Established Connection and a Potential Strategy for Precision Oncology

Glioblastoma multiforme is an acute and severe form of primary malignancy in the brain. Recent research has focused increasing attention on understanding the complex relationship between the gut-immune-brain axis and brain malignancies. The gut microbiota and the immune system interact to maintain gut homeostasis through various neurotransmitters, bacterial metabolites, and products that can travel to the glioma immune microenvironment via the vagal/lymphatic/blood pathways. Increasing evidence indicates that modulating the composition of the gut microbiome and neurotransmitters affects the neuronal progenitors and glial cells, thus the tumor cells’ growth. This chapter highlights proposed mechanisms of the gut microbiota’s influence on glioma development and progression and provides new insights for microbiome-mediated precision oncology.