Researchers at the University of California San Diego have found that the mouths of those who suffer from migraine headaches have significantly more microbes with the ability to modify nitrates than people who do not have headaches. Many of the millions of Americans who suffer from migraines report an association between consuming foods with nitrates and the intensity of their headaches. The researchers were interested in exploring the idea that foods can trigger migraines and in particular exploring the microbiome connection with migraines. In addition, four in five cardiac patients who take nitrate-containing drugs often report headaches as a side effect.
Nitrates are found in foods including processed meats and green leafy vegetables. Nitrite reducing bacteria found in the mouth can reduce the nitrates to nitrites. These nitrites can then be converted to nitric oxide when circulating in blood. Nitric oxide can help improve cardiovascular health by reducing blood pressure.
Using publicly available data from the American Gut Project, the researchers sequenced bacteria found in 172 oral samples and 1,996 fecal samples from healthy study participants. The people who the samples were obtained from had filled out surveys indicating whether they suffered from migraine headaches. The bacterial gene sequencing found that bacterial species were found in different abundances between people who have migraines when compared to those who don’t.
The team then used a bioinformatic tool called PICRUSt to analyze which genes were likely to be present in the two different sets of samples, given the bacterial species present. In fecal samples, they found a small statistically significant increase in the abundance of genes that encode nitrate, nitrite and nitric oxide-related enzymes in those who suffer from migraines. In oral samples, these genes were significantly more abundant in those who suffer from migraines.
The researchers feel that the conversion from nitrates to nitrites in the mouth is advantageous to cardiovascular health. However, now they know that more of this going on can result in migraine headaches or may be a cause of migraine headaches occurring. The researchers have plans to look at more patients and group by different types of migraines. The researchers can then better find out if oral microbes really do have nitrate-reducing genes and measure their levels of circulating nitric oxide allowing them to gain insight into migraine headaches.
This is interesting work and helps solidify the experience that many migraine sufferers have, that their diet can play a role in their headaches. See for example a prior blog post at http://blog.teethremoval.com/a-healthy-headache-diet/.
Source: Antonio Gonzalez and et al., Migraines Are Correlated with Higher Levels of Nitrate-, Nitrite-, and Nitric Oxide-Reducing Oral Microbes in the American Gut Project Cohort, mSystems, October 2016.