Certain bacteria in the mouth cause migraines. This is what researchers from the San Diego School of Medicine (USA) suggest in the mSystems journal. Using state-of-the-art techniques, researchers have found higher levels of certain oral bacteria in migraine sufferers compared to those without headaches.
Oral bacteria involved
The research team took 343 mouth swabs from migraine and non-migraine sufferers. The volunteers also told the scientists about their diet and the frequency of their headaches. Verdict: the rate of Rothia mucilaginosa and Haemophilus parainfluenzae bacteria were higher in those with headaches, without the distribution of other bacterial species in the mouth being different.
However, Rothia mucilaginosa and Haemophilus parainfluenzae have the particularity of reducing nitrates, present in our food (chocolate, wine, meats, green vegetables, etc.) but also in medicines.
This chemical reaction transforms nitrates into nitrites and nitric oxides, essential elements for the proper functioning of the cardiovascular system (nitric oxides improve blood circulation and reduce blood pressure). A transformation that the human body cannot do without these bacteria.
Nitrates plus inflammation equals migraine
Affecting 11 million people in France, migraine is thought to result from nerve stimulation which leads to inflammation of neurons and dilation of cerebral vessels, in particular the arteries of the meninges (membranes protecting the brain, brainstem and spinal cord).
During a dietary or medicinal intake of an element rich in nitrates, these bacteria present in the mouth then massively degrade the nitrate, which behave as pro-inflammatory agents, which could trigger migraine attacks.
The link had already been noticed in previous work, which notably showed that 4 out of 5 heart patients taking medications containing nitrates regularly suffer from headaches.