Preoperative gut microbiota depletion and metabolomic signatures predict postoperative pneumonia in patients with intracranial space-occupying lesions: a multi-omics prospective cohort study.

BACKGROUND

Patients with intracranial space-occupying lesions are highly susceptible to postoperative pneumonia (POP) due to extensive surgical trauma, impaired consciousness, and prolonged immobilization, which severely compromise recovery and increase mortality. While the "gut-lung axis" highlights the role of gut microbiota in distal pulmonary immune regulation, how preoperative gut signatures predict neurosurgical infections remains poorly understood.

METHODS

This prospective study enrolled 50 patients, collecting preoperative and postoperative fecal and plasma samples. 16S rDNA sequencing was used to monitor microbial evolution, and LC-MS/MS-based untargeted metabolomics characterized systemic metabolic profiles.

RESULTS

Although surgical stress reduced microbial diversity across all groups, the POP group exhibited significant preoperative depletion of Roseburia. Metabolomics revealed a preoperative "metabolic deficiency" state in POP patients, primarily involving impaired fructose and mannose metabolism. Multi-omics integration confirmed that preoperative Roseburia abundance positively correlated with the anti-inflammatory metabolite 1-methylnicotinamide. A metabolic signature composed of the top 10 preoperative metabolites predicted POP with an AUC of 1.0.

CONCLUSION

The disruption of metabolic homeostasis driven by preoperative gut microbiota depletion is a key factor associated with POP susceptibility. Monitoring the preoperative metabolic signature enables precise identification of high-risk individuals and offers a novel pathway for early intervention via the gut-lung axis.