The MIT team, working with researchers in Germany, found that in both mice and humans, a high-salt diet shrinks the population of a certain type of beneficial bacteria. As a result, pro-inflammatory immune cells called Th-17 cells grow in number. These immune cells have been linked with high blood pressure, although the exact mechanism of how they contribute to hypertension is not yet known.
The researchers further showed that treatment with a probiotic could reverse these effects, but they caution that people should not interpret the findings as license to eat as much salt as they want, as long as they take a probiotic.
“I think certainly there’s some promise in developing probiotics that could be targeted to possibly fixing some of the effects of a high-salt diet, but people shouldn’t think they can eat fast food and then pop a probiotic, and it will be canceled out,” says Eric Alm, director of MIT’s Center for Microbiome Informatics and Therapeutics and a professor of biological engineering and civil and environmental engineering at MIT.
Alm, Dominik Muller of the Max-Delbruck Center for Molecular Medicine in Berlin, and Ralf Linker of Friedrich-Alexander University in Erlangen, Germany, are the senior authors of the study, which appears in the Nov. 15th issue of Nature. The paper’s lead author is Nicola Wilck of the Max-Delbruck Center for Molecular Medicine. Authors from MIT include graduate students Mariana Matus and Sean Kearney, and recent PhD recipient Scott Olesen.