Distinct Gut Microbiota Profiles in Unruptured and Ruptured Intracranial Aneurysms: Focus on Butyrate-Producing Bacteria.

Gut microbiome composition may influence the risk of intracranial aneurysm rupture. : This study analyzed the gut microbiota of 48 patients-24 with ruptured aneurysms (RA) and 24 with unruptured intracranial aneurysms (UIA)-using next-generation sequencing. : While alpha diversity was similar between groups, beta diversity revealed significant taxonomic differences (Bray-Curtis: = 0.02; unweighted UniFrac: = 0.0291). Both groups were dominated by the phyla , , and , but genus- and family-level differences were observed. RA patients showed higher abundances of , , , , and , whereas UIA patients exhibited greater levels of , , , , and . Linear discriminant analysis identified one class, 10 genera, and 17 species that differed significantly between groups. Notably, and -bacteria known for their anti-inflammatory and neuroprotective properties-were enriched in UIA patients. These findings suggest that gut microbiota, particularly short-chain fatty acid-producing bacteria, may contribute to vascular protection and aneurysm pathophysiology. Microbiome-based therapeutic strategies could offer new avenues for the prevention of cerebrovascular disease.