The research showed that migraine sufferers had higher levels of bacteria that are known to be involved in processing nitrates, which are typically found in processed meats, leafy vegetables and some wines. Read more 
 
 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.” 
 
 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 aid cardiovascular health by boosting circulation. According to new research, though, one possible cause of migraines may be bacteria in your mouth.For the study , published online today in the journal mSystems, researchers used data from the American Gut Project to analyze 172 samples of bacteria taken from participants' mouths — and 1,996 taken from their poop. Diet, stress and lack of sleep are all known to be triggers, and hormones are also thought to play a role - migraine affects three times as many women as men. Normally, those nitrates eventually get turned into nitric oxide — which can be good for your heart health , but which has also previously been linked to migraines .
– Certain foods like chocolate, wine, and processed meats have long been linked to migraines, and while nitrates in those foods are often seen as the culprit, it's not entirely clear why some people are more susceptible to ensuing headaches than others, reports Quartz. Now scientists are reporting in the journal mSystems that, thanks to an analysis of 2,200 people participating in the American Gut Project, they've found that people with migraines tend to have more oral bacteria that process nitrates, reports Refinery29. This means that people suffering from migraines could be creating more nitric oxide, which has been linked to migraines, as they process those nitrates. Scientists next plan to study the diets of people with migraines to look for links between nitric oxide levels in their blood and migraines, which would help confirm that nitrate-processing oral bacteria are behind the headaches. If that's true, we could eventually see a "magical probiotic mouthwash" that helps reshape oral bacteria to prevent migraines, reports the Guardian. In the meantime, researchers say, people who suspect that nitrates are behind their migraines should try to avoid them when possible—which could be difficult, considering they're also present in leafy greens. (The source of this man's headache was highly unusual, and more than a little gross.)