Gut brain axis and gut microbiome in glioblastoma. Associations, treatment and outcomes

Most of the fundamental functions of the body hinge on the gut-brain axis which is a complex communication system connecting gut and brain. Recent studies show that the gut microbiome plays a significant role in the growth and progression of glioblastoma (GBM), influenced through this gut-brain connection. This review focuses on the recent development in gut brain axis and gut microbiome in GBM, including their roles in the immune system, and the results of treatment. We conducted a broad review to explore how the gut microbiota affects neurotransmitters, the immune system, and the blood-brain barrier (BBB) in GBM by analysing the recent studies published in PubMed, Google Scholar, Scopus, and Elsevier. Findings suggest that the gut microbiota population affects the GBM progression and sustenance. Also, it is observed that there is significant influence of gut microbiota in novel treatment strategies of GBM such as immunotherapy. The gut-brain axis plays an important role GBM progression. Changing the gut microbiota could be a useful treatment strategy. Future studies are required to further explore in which specific microbes are involved in order to identify microbiota-based markers to improve GBM treatments • Study Scope: This review explores the gut-brain axis and gut microbiome's role in glioblastoma (GBM) progression, immune modulation, and treatment outcomes. • Microbiota Influence: Gut microbiota regulates neurotransmitters, immune responses, and blood-brain barrier integrity, affecting GBM growth and survival. • Metabolic Impact: Microbial metabolites like SCFAs and tryptophan derivatives influence tumor proliferation and immune evasion. • Therapeutic Potential: Gut microbiota modulation, including probiotics and prebiotics, could enhance glioblastoma treatments like chemotherapy and immunotherapy. • Future Directions: Identifying microbial biomarkers may improve early GBM detection, prognosis, and personalized therapeutic strategies.