Miso a fermented soybean paste, often used in Japanese cooking. It contains probiotics that aid digestive health and help form Vitamin K. Miso is high in sodium (1 Tbsp has a quarter of the daily recommended allowance), but studies show it may not raise blood pressure like table salt.
Miso is commonly found in plastic or glass tubs in the Asian foods aisle at your grocery store. It comes in three varieties - white, yellow, and red. The darker the miso, the longer it's been fermented. The longer the fermentation the stronger and saltier it will taste. You can store miso in the fridge for up to 1 year.