How Mouth Bacteria May Cause Migraines

Do you suffer from migraines? Oddly enough, the bacteria in your mouth may cause your severe headaches. In a study conducted by the Center for Microbiome Innovation at the University of California at San Diego, patients who suffer from migraines have an increased population of nitrites in their saliva. Researchers took oral and fecal data from the American Gut Project and sequenced it through PICRUSt, a technology that analyzes genes present in bacterial samples. Participants were also asked if they suffer from migraines in a study questionnaire. While there was little to no difference in the type of bacterial species present in migraine and non-migraine sufferers, the abundance of certain enzymes like nitrate, nitrite and nitric oxide was noticeable. Nitrate is a compound that is found naturally in vegetables, but can also be added as a preservative in processed foods. Foods with high nitrate levels include leafy vegetables, processed meats, chocolate and wine. Nitrates convert to nitrites in the saliva, then into nitric oxide or nitrosamines after entering the body. Nitric oxide can boost cardiovascular health, improve blood flow and lower blood pressure. Contrastingly, nitrosamines increase your stomach’s acidity and hold carcinogens found in tobacco smoke. “We thought that perhaps there are connections between what people are eating, their microbiomes and their experience with migraines,” said Rob Knight, a programmer analyst for the study. Nitrosamine occurs when food with nitrates are exposed to high heat. Processed meats like bacon and hot dogs are known for higher levels of nitrosamine through this. Knight concluded that the type of food you eat directly affects your migraine risk. “We know for a fact that nitrate-reducing bacteria are found in the oral cavity. We definitely think this pathway is advantageous to cardiovascular health,” Knight added. Migraines affect around 38 million people in the United States alone. While the cause is unclear, a variety of “triggers” have been identified including weather, stress, hormone changes and physical exertion. Migraine attacks can cause a severe pulsing pain in your head, typically on one side more than the other. Other symptoms include vomiting, nausea and sensitivity to light and noise. After publishing the study in the journal mSystems, Knight hopes his results will help future researchers understand how microbes relate to migraines. Although Knight did not fully conclude whether microbes are a cause or an effect of migraines, he is one step closer to figuring out that role. For his next study, Knight plans to place individuals who suffer from migraines into subgroups. This may potentially figure out patterns between different types of migraines and the bacteria identified in these individuals’ mouths. “We now have the 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.”