Nature (15 Nov. 2017) doi:10.1038/nature24628

A high-salt diet (HSD) has well-established links to cardiovascular disease and is also increasingly appreciated as driving the differentiation of pathogenic cells in the TH17 subset of helper T cells. In Nature, Müller and colleagues investigate whether an HSD can also perturb gut microbiota and whether this affects, at least in part, pathogenic TH17 cells. Mice maintained on an HSD show the expected elevation in blood pressure, but also a greater frequency of TH17 cells in the gut. Accordingly, mice fed an HSD exhibit exacerbated experimental autoimmune encephalitis. The HSD does not elicit gross alterations in the microbiome but instead seems to selectively deplete mice of Lactobacillus murinus. Administration of L. murinus to mice fed an HSD might normalize their otherwise elevated frequency of TH17 cells and ameliorate experimental autoimmune encephalitis. As with mice, male human volunteers on an HSD showed an increased frequency of TH17 cells in the blood and a generalized reduction in Lactobacillus genera. Salt-induced perturbations of the gut microbiota can therefore influence the differentiation of TH17 cells and subsequent manifestations of autoimmune disease and cardiovascular disease. ZF