Unveiling Gut Microbiota Divergence in Sellar-Parasellar Masses and Brain Tumors: A Link Beyond the Skull

This study explored gut microbiota composition and metabolic profiles in patients with sellar-parasellar tumors (SPT), other brain tumor types (OBT, predominantly aggressive tumors), and healthy controls (HC) to identify microbial and metabolic biomarkers for brain tumor phenotypes. A total of 56 participants were included in the study, comprising SPT patients (n = 17), OBT patients (n = 11), and HC (n = 28). Gut microbiota were analyzed via 16S rRNA sequencing, and metabolic profiles were assessed using MICOM pipeline simulations. Advanced statistical models, including multivariable regression and AI-driven XGBoost classification, evaluated microbial and metabolic differences among groups.Tumor patients showed reduced alpha diversity and significant beta diversity shifts compared to controls. Healthy individuals exhibited higher levels of Lachnospira and Comamonadaceae, while tumor patients had an overrepresentation of Bacilli. Metabolic simulations revealed elevated metabolic exchange scores (MES) for 19 metabolites in OBT patients, especially those involved in amino acid, lipid, and carbohydrate metabolism. Aggressive tumors exhibited distinct metabolic rewiring, including increased glycolysis, lipid metabolism, and amino acid pathways, while SPT had profiles closer to healthy controls. As a part of metabolit production and consumer chain, taxa like Faecalibacterium demonstrated differentiation based on diversity, while Akkermansia and Lachnospira were more abundance-dependent. These findings emphasize the role of gut microbiota in brain tumor progression through altered metabolic pathways, offering potential biomarkers and therapeutic targets for brain tumor management. The integration of AI tools highlights their utility in uncovering complex microbial and metabolic dynamics. Further longitudinal studies are required to confirm these results and clarify causality.