Scientists have found that migraine sufferers tend to have a different mix of bacteria in their mouth and gut compared to non-migraine suffers. This increased level of bacteria potentially makes them more susceptible to the debilitating headaches due to it causing sufferers an increased sensitivity to certain foods.
People who suffer from migraines often say that eating certain foods trigger their headaches, but according to the new study published on Oct. 18 in mSystems, it might not be the actual foods that trigger the migraine, but rather an increased level of bacteria in their mouths that cause the reaction.
Conducted by researchers at University of California San Diego School of Medicine, the study offers a potential explanation for why some people are more susceptible to debilitating headaches and why some foods appear to act as triggers for migraines.
Antonio Gonzalez, a programmer analyst at the University of California San Diego and the study’s first author, said: “There is this idea out there that certain foods trigger migraines – chocolate, wine and especially foods containing nitrates. We thought that perhaps there are connections between what people are eating, their microbiomes and their experiences with migraines.”
The results of the study indicate that migraine sufferers have significantly higher levels of bacteria in their mouths and guts that are known to be involved in processing nitrates, which are typically found in processed meats, leafy vegetables and some wines. For some migraine suffers, these specific foods can trigger severe headaches, although they do not appear to be a trigger for other people.
For their research, the team analyzed the bacteria found from 172 oral samples and 1,996 fecal samples taken from healthy participants, who had previously reported whether they were affected by migraines. In the oral samples, the researchers found “significantly more abundant” genes that reduce and break down nitrates in people who suffer from migraines, compared to those who do not. The fecal samples showed a slight but statistically significant increase in the abundance of these genes.
When nitrates in food are broken down by bacteria in the mouth and gut they are eventually converted into nitric oxide in the blood stream, a chemical that dilates blood vessels and can improve blood flow and circulation.
The study’s findings raise the possibility that migraines could be triggered when nitrates in food are broken down more efficiently, causing vessels in the brain and scalp to dilate.
Around one in seven people suffer from migraines, although migraines tend to me as much as three times more common for woman than for men. A majority of migraine suffers have an attack more than once a month and about half being severely affected when they get a migraine. Typical migraine symptoms include a throbbing headache, nausea and lethargy. Some people also experience a visual aura, which appears as shimmering light in the peripheral vision.
Although diet, stress lack of sleep, and hormones are all thought to be triggers, and hormones are also thought to play a role – migraine affects three times as many women as men.
The results of the study mark a small but important step towards better understanding migraines. Although diet, stress lack of sleep, and hormones are all thought to be triggers, scientist and doctors still do not fully understand the causes behind the debilitating headaches.
Gonzalez and his team are planning to expand on the study in the next couple of months, including implementing a controlled diet study for migraine sufferers to see whether nitric oxide levels in the bloodstream are linked to migraine attacks.
“We think it will be possible to… classify different migraine sufferers’ status based on these bacteria,” said Gonzalez. He added that by classifying migraine types, scientists could better understand how to prevent or treat different triggers.