While you may have heard about probiotics, you may be less familiar with kefir. It can be pronounced keh-feer, kee-fur, or kef-fur. No matter which way you say it, it’s pretty popular in natural health circles. That’s because it contains nutrients as well as friendly bacteria that can help you maintain a healthy gut.

Is kefir just one of those passing fads with health claims that don’t pan out, or could it contribute valuable nutrition to your diet?

What is Kefir?

Kefir is a fermented beverage made from what kefir drinkers and producers call “grains.” However, these grains are not grown from plants. They are not a cereal or anything that resembles a grain from the food pyramid.

Kefir grains are made up of yeasts and bacteria (1). They are small, translucent, whitish, jelly-like orbs that look a little like tiny pieces of cauliflower.

There are two types of kefir: water and milk.

Water Kefir

water kefir grains and water kefir compared

Water kefir grains are comprised primarily of Lactobacillus brevis, Streptococcus lactis and Saccharomyces cerevisiae (2).

However, other bacteria and yeasts have been found in and on water kefir grains (1).

When added to a mixture of sugar, water, and dried fruit, the water kefir grains ferment the beverage by consuming the sugars and minerals and releasing beneficial bacteria that can then colonize your gut.

Water kefir grains are also referred to as Tibi, sugary kefir grains and gingerbeer plants (1).

Milk Kefir

Milk kefir grains consist primarily of Lactobacillus kefiri bacteria (3).

milk kefir grains and milk kefir compared

Milk kefir grains are added to milk.  As they consume the lactose, they release probiotics and other compounds into the beverage (4). After about 24 hours, the grains are strained from the liquid. You can drink the beverage that now contains probiotics, and you can use the grains to make another batch of kefir.

The grains last indefinitely as long as they are “fed” the proper ratios of liquid, nutrients and sugar. Different studies have found different types of bacteria in both water and milk kefir grains (3).  However, more research has been conducted on milk kefir than water kefir (1).

You can make either type of kefir at home if you can get your hands on the grains, which are often sold online and may be available at health food stores. Milk kefir is often sold commercially in prepackaged bottles. This makes it more accessible and convenient for many people.