Two - sample Mendelian randomization: intestinal flora and migraine.

Objective To investigate the causal relationship between 211 intestinal flora and migraine using a two - sample Mendelian randomization method. Methods Independent genetic loci significantly associated with the relative abundance of 211 intestinal flora were extracted according to a predefined threshold using GWAS data for intestinal flora from the public database MiBioGen consortium study (n = 13 266) and GWAS data for migraine from the Finnish database ( The FinnGen Biobank) (n = 280 567 ) as instrumental variables (IVs) . Analyses were mainly performed using the inverse variance weighting method, and results were assessed according to the Odds ratio (OR) and 95% confidence interval (95% CI) of the effect indicators. The stability and reliability of the results were verified using the leave - one - out method, heterogeneity test, and horizontal genetic pleiotropy test. Results Elevated abundance of Bifidobacteriales, Bifidobacteriaceae, and Bifidobacterium reduced the risk of migraine with a dominance ratio and confidence interval of (OR = 0. 77, 95% CI :0. 70 - 0.83), (OR =0.77, 95% CI :0. 70 - 0. 83 ), and (OR =0.82, 95% CI :0. 74 -0.91), respectively. The leave - one - out analysis showed stable results, with no instrumental variables that had a strong effect on the results, and the effects of heterogeneity and horizontal genetic pleiotropy on the estimation of causal effects could be removed. Conclusion Bifidobacteriales, Bifidobacteriaceae, and Bifidobacterium are protective factors for the occurrence of migraine, and with increased abundance of flora able to reduce the onset of migraine and clinical medication, probiotics for migraine may become a future trend. [ABSTRACT FROM AUTHOR]