Migraines could be caused by gut bacteria, study suggests

On average, migraine sufferers were found to have significantly higher levels of nitrate-modifying bacteria in their mouths and guts. (© 9nong/Istock.com)

On average, migraine sufferers were found to have significantly higher levels of nitrate-modifying bacteria in their mouths and guts.

An American study has found that migraine sufferers have higher levels of oral bacteria that break down nitrates, which could trigger headaches.

Researchers from the University of San Diego have identified a difference in the levels of specific bacteria in the mouth, throat and gut of patients who suffer from migraines. Compared to healthy participants, migraine sufferers were found to have higher levels of the bacteria that convert nitrates into nitric oxide in the blood, which can lead to headaches.

Nitrates are found in foods such as processed meats like bacon and salami, as well as wine, chocolate, leafy vegetables and certain medications.

The researchers analyzed fecal samples from 171 migraine sufferers compared with 172 oral samples and 1,996 fecal samples from healthy participants.

They found that, on average, migraine sufferers had significantly higher levels of nitrate-modifying bacteria in their mouths and guts than healthy participants.

Previously, researchers observed that around four in five cardiac patients who take nitrate-containing medication to treat chest pains or congestive heart failure report severe headaches as a side effect.

"We now also have a potential connection to migraines, though it remains to be seen whether these bacteria are a cause or result of migraines, or are indirectly linked in some other way," explains Dr Embriette Hyde, contributor and project manager for the American Gut Project.

The next step for the scientists is to explore the potential links between nitrate-modifying bacteria and different types of migraines.

The findings were published in the journal mSystems.