科学美国人60秒:Salty Skin Boosts Mouse Wound Healing

It’s both painful and insulting to rub salt in a wound. But a new study shows that salty skin can actually ward off infections, at least in mice fed a high-sodium diet. That’s according to a study in the journal Cell Metabolism. [Jonathan Jantsch et al, Cutaneous Na⁺ Storage Strengthens the Antimicrobial Barrier Function of the Skin and Boosts Macrophage-Driven Host Defense]

We tend to think of dietary salt as a health threat. And it is. Too much sodium has been linked to high blood pressure and an increased risk for heart attack and stroke. But we also crave salty snacks and store the accumulated sodium in our bodies, particularly in the skin. 

A clue to explaining this paradox came when researchers noticed that mice that were attacked by a cage mate wound up with an unusually large amount of sodium at the site of the bite. They then found high sodium levels in people at the locations of bacterial skin infections. 

So the researchers fed mice a high-sodium diet. And found that the dietary salt boosted the activity of immune cells in the animals’ skin, which gave them a leg up when it came to healing their wounds. 

The findings could lead to treatments that would help us assault infections without having to resort to pretzels, potato chips or pickles.

—Karen Hopkin