Eating more salt might raise your blood pressure, especially if it changes the bacteria in your gut — which could be one way your diet affects heart health.

What we've found so far suggests that eating more salt might affect blood pressure through changes in the gut microbiome. The evidence we’ve reviewed leans toward this idea, with all 20.0 supporting assertions pointing in the same direction and none refuting it [1]. Our analysis of the available research shows that salt intake could influence blood pressure not just directly, but also indirectly by altering the types of bacteria in your gut. These microbes play a role in many body functions, including how your immune system and metabolism work. When salt levels go up, some studies suggest certain gut bacteria may decrease, especially those linked to reducing inflammation and helping regulate blood pressure [1]. This shift might contribute to higher blood pressure over time, though we don’t yet know exactly how strong this effect is or how it plays out in different people. We want to be clear: this is not proof that salt raises blood pressure solely through the gut. What we’re seeing is a possible pathway—one way diet might influence heart health. The exact mechanisms are still unclear, and we don’t have enough data to say how much salt is “too much” for your gut bacteria, or whether fixing gut health can fully offset salt’s effects. Based on what we’ve reviewed so far, changes in the gut microbiome appear to be one piece of the puzzle linking high salt intake to blood pressure. But we’re still building the full picture. Practical takeaway: If you're concerned about blood pressure, watching your salt intake makes sense—and what you eat also affects your gut bacteria. Eating more fiber-rich plants may help support a healthier gut, which could, in turn, support heart health.