Introduction:
Meningioma, a prevalent intracranial tumor, presents diagnostic and therapeutic challenges due to its heterogeneous nature. Metabolic profiling has emerged as a promising approach to elucidate its underlying molecular mechanisms and discover potential biomarkers.

Material and methods:
This study employed bidirectional Mendelian randomization (MR) analysis to investigate the causal relationship between plasma metabolites and meningioma risk. Genetic instruments were utilized as surrogates for both plasma metabolites and meningioma, allowing MR analysis in both directions to assess the impact of metabolites on meningioma risk and vice versa. This study encompassed 1400 plasma metabolites and 314,708 participants (1316 individuals diagnosed with meningioma and 313,392 individuals diagnosed without meningioma).

Results:
Initially, 46 plasma metabolites were found to be associated with meningioma risk (p<0.05), with 23 plasma metabolites associated with a decreased risk and 23 plasma metabolites associated with an increased risk of meningioma. Furthermore, the identified relationships between the 46 plasma metabolites and meningioma showed no significant horizontal pleiotropy (p>0.05), suggesting that the results are not influenced by other confounding factors. Reverse MR analysis elucidates that meningioma has no significant impact on the levels of 24 plasma metabolites, and is unaffected by confounding factors. In addition, the identified plasma metabolites influence the occurrence of meningioma through nine metabolic pathways.

Conclusions:
The findings of this bidirectional MR study indicate that 24 plasma metabolites significantly lead to an increased/decreased risk of meningioma, suggesting that the plasma metabolite profile characteristics serve as important serological tools for the early diagnosis of meningioma.