This study provides the first evidence of gut dysbiosis in grade I meningioma, characterized by Escherichia_Shigella dominance and depletion of immunomodulatory commensals, a signature that correlates with increased intratumoral immune infiltration and holds promise as a novel biomarker.
Meningioma patients exhibited significantly reduced gut microbiota alpha diversity compared to healthy controls.
Proteobacteria were markedly enriched in meningioma patients compared to healthy controls at the phylum level.
Escherichia_Shigella demonstrated high diagnostic accuracy for WHO grade I meningioma detection.
Escherichia_Shigella abundance positively correlated with intratumoral immune cell densities across multiple immune cell types.
This study represents the first characterization of gut microbiota composition and its association with tumor immune features in meningioma patients.
This research suggests that patients with a common type of brain tumor called meningioma have a distinctly different community of gut bacteria compared to healthy people. Specifically, meningioma patients had far less diversity in their gut microbiome overall, and showed a dramatic increase in a group of bacteria called Escherichia_Shigella (about 26% of their gut bacteria vs. only 1.6% in healthy controls), while beneficial bacteria like Bacteroidaceae and Ruminococcaceae were reduced. These findings came from analyzing stool samples from 15 meningioma patients and 15 healthy individuals using a technique called 16S rRNA sequencing. This research also suggests that the level of Escherichia_Shigella in a person's gut was closely linked to the degree of immune cell activity inside the tumor itself — patients with more of this bacterium had more neutrophils, macrophages, and T cells infiltrating their tumors. The pattern of gut bacteria was also highly accurate at distinguishing meningioma patients from healthy controls, with a diagnostic accuracy of about 95%, raising the possibility that gut microbiome analysis could one day serve as a non-invasive biomarker for this tumor type. This is the first study to examine gut bacteria in meningioma patients, and it opens a new line of investigation into how the gut-brain connection might influence brain tumor biology and the immune environment within tumors. While the study was small and cannot establish causation, it points to potential links between gut microbiome dysbiosis, neuroinflammation, and meningioma that warrant further investigation in larger studies.
Yin K, Ma S, Yang J, Feng M, Zuo Y, Wang F. (2026). Gut microbiota composition and tumor immune features in meningioma patients.. Microbiology spectrum. https://doi.org/10.1128/spectrum.02485-25