Objectives: The presence of intestinal flora in the gut has been linked to migraines in recent studies, but whether the association is causal or due to bias remains to be clarified. We aimed to explore whether there is a potential causal relationship between gut microbiota and migraine risk with this study.
Materials and methods: We conducted a two-sample Mendelian randomized analysis study to explore whether gut microbiota has a causal relationship with migraine using publicly available data from large-scale genome-wide association studies. The inverse variance weighting was used as the main method, and weighted median and MR-Egger were used as supplementary methods for causal inference. Sensitivity analyses, including leave-one-out analysis, Cochran Q test, and MR-Egger intercept test, were used to verify the robustness of the results.
Results: After rigorous quality control of the results, we identified that genetic predisposition towards a higher abundance of genus.Lactobacillus was causally associated with higher of migraine (IVW OR = 1.10, 95% CI = 1.03 - 1.18, p = .004), whereas the higher abundance of family.Prvotellaceae predicted a decreased risk of migraine (IVW OR = 0.89, 95% CI = 0.80 - 0.98, p = .02). Sensitivity analyses indicated the results were not biased by pleiotropy.
Conclusion: According to our research, there is evidence showing that gut microbiota may be involved in migraine development, which suggested that a stool examination might be helpful to recognize those with a higher risk of migraine. Further mechanisms remained to be elucidated in future studies.
Keywords: Migraine; causality; gut microbiota; mendelian randomization.