Migraine sufferers’ lips have much more microorganisms that can change nitrates than persons who don’t experience migraine headaches, according to researchers at the University of California San Diego School of Medicine. mSystems released the study on October 18, 2016.
A migraine is a headache that is usually moderate or severe and causes throbbing pain on one side of the brain. Many people also experience symptoms like nausea, vomiting, and increased sensitivity to light and sound.
“There is this idea out there that certain foods trigger migraines chocolate, wine, and especially foods containing nitrates,” said first author Antonio Gonzalez, a programmer analyst in the laboratory of Rob Knight, PhD, professor, and director of the Center for Microbiome Innovation at UC San Diego and senior author on the study.
“We thought that perhaps there are connections between what people are eating, their microbiome, and their experiences with migraines.”
Migraine is a frequent health problem that affects one out of every five women and one out of every fifteen males. Early adulthood is when they normally start. Some people suffer from migraines on a regular basis, up to several times per week. Others only get migraines once in a while.
Many of the 38 million Americans who suffer from migraines attribute their severe headaches to nitrate use. Nitrates can be converted to nitrites by bacteria in the mouth, which can be found in meals such processed meats and green leafy vegetables, as well as some medicines.
There is this idea out there that certain foods trigger migraines chocolate, wine, and especially foods containing nitrates.
Antonio Gonzalez
Under some conditions, these nitrites can be converted to nitric oxide while circulating in the blood. Nitric oxide improves blood flow and lowers blood pressure, which is beneficial to cardiovascular health.
Approximately four out of every five cardiac patients who use nitrate-containing medications for chest discomfort or congestive heart failure get severe headaches as a side effect.
Gonzalez and collaborator Embriette Hyde, PhD, sequenced bacteria discovered in 172 oral samples and 1,996 fecal samples from healthy volunteers using publically available data from the American Gut Project, a crowdfunded citizen science endeavor overseen by the Knight lab. The individuals had previously completed questionnaires indicating whether or not they had migraines.
The bacterial gene sequencing revealed that different bacterial species were identified in varied abundances in migraineeurs and non-migraineurs. In terms of bacterial community composition, the researchers found no significant differences between migraineurs and non-migraineurs in either fecal or oral samples.
Given the bacterial species present, the scientists utilized a bioinformatics tool called PICRUSt to determine which genes were likely to be present in the two sets of samples.
In migraineurs’ feces, they discovered a small but statistically significant increase in the number of genes encoding nitrate, nitrite, and nitric oxide-related enzymes. These genes were substantially more prevalent in migraineurs’ oral samples.
“We know for a fact that nitrate-reducing bacteria are found in the oral cavity,” said Hyde, project manager for the American Gut Project and assistant project scientist in the Knight lab.
“We definitely think this pathway is advantageous to cardiovascular health. 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.”
The next stage, according to Gonzalez and Hyde, will be to look at more defined groups of patients, segregated into the many forms of migraines.
Researchers can then see if their oral microorganisms do indeed express those nitrate-reducing genes, as well as monitor their circulation nitric oxide levels and see how they link to migraine status.
