Gut Bacteria Are Sensitive To Salt, Study Says- Latest News
We eat salt every day, sometimes more, sometimes less, but often too much. “But so far, nobody had studied how salt affects the bacteria in the gut,” says head of the study Professor Dominik Müller of the Berlin Experimental and Clinical Research Center (ECRC) and the Berlin Institute of Health (BIH), both of which are joint institutions within the Max Delbrück Center for Molecular Medicine and the Charité – Universitätsmedizin Berlin.
The role played by bacteria in the most diverse diseases is becoming an ever more important focus of research. Just how the organism interacts with gut flora is, however, still largely unknown.
A Western lifestyle with high salt consumption can lead to hypertension and cardiovascular disease. High salt may additionally drive autoimmunity by inducing T helper 17 (TH17) cells, which can also contribute to hypertension. Induction of TH17 cells depends on gut microbiota; however, the effect of salt on the gut microbiome is unknown.
Now Müller and his team have demonstrated that excess salt decimates the lactobacilli in the gut while blood pressure rises and the number of Th17 helper cells is increased. These immune cells are associated with
hypertension and autoimmune diseases like MS.The researchers used mice in order to observe the gut microbiomes fed either a normal or high-salt diet. Their results showed that high levels of dietary salt caused gut populations of Lactobacillus species to drop dramatically, in parallel with the animals developing higher blood pressure and producing increased numbers of TH17 cells.
However, when animals fed a high-salt diet were also given oral probiotics of Lactobacillus murinus, their blood pressure levels and numbers of TH17 cells dropped. “Thus, L. murinus prevents HSD [high-salt diet]-induced generation of TH17 cells and consequently ameliorates salt-sensitive hypertension,” the authors write.
Apart from the experiments on mice, the researchers also investigated the bacterial community in the digestive tract of twelve healthy men who were given six extra grams of salt every day for a fortnight. As the test subjects otherwise maintained their usual eating habits, they thus roughly doubled their daily intake of salt. Here, too, the lactobacilli responded sensitively. Most of them were no longer detectable after 14 days of increased salt intake. At the same time, scientists discovered that the probands’ blood pressure rose and the number of Th17 helper cells in the blood increased.
“Our study goes beyond just describing the changes caused by salt. We want to consider interrelated processes,” says Müller. But so far, they have not managed to completely elucidate the precise interactions, he explains. “We can’t exclude the possibility that there are other salt-sensitive bacteria that are just as important.”
