Kefir is all the rage in the natural health community.

High in nutrients and probiotics, it is very beneficial for digestion and gut health.

Many people consider it to be healthier than yogurt.

Here are 9 health benefits of kefir that are supported by research.

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Kefir is a fermented drink, traditionally made using cow's milk or goat's milk.

It is made by adding kefir grains to milk. These are not cereal grains, but grain-like colonies of yeast and lactic acid bacteria that resemble a cauliflower in appearance.

Over approximately 24 hours, the microorganisms in the kefir grains multiply and ferment the sugars in the milk, turning it into kefir.

Then the grains are removed from the liquid and can be used again.

In other words, kefir is the drink, but kefir grains are the starter culture that you use to produce the beverage.

Kefir originated from parts of Eastern Europe and Southwest Asia. The name is derived from the Turkish word keyif, which means "feeling good" after eating (1).

The grains’ lactic acid bacteria turn the milk’s lactose into lactic acid, so kefir tastes sour like yogurt — but has a thinner consistency.

A 6-ounce (175-ml) serving of low-fat kefir contains (2):

  • Protein: 4 grams
  • Calcium: 10% of the RDI
  • Phosphorus: 15% of the RDI
  • Vitamin B12: 12% of the RDI
  • Riboflavin (B2): 10% of the RDI
  • Magnesium: 3% of the RDI
  • A decent amount of vitamin D

In addition, kefir has about 100 calories, 7–8 grams of carbs and 3–6 grams of fat, depending on the type of milk used.

Kefir also contains a wide variety of bioactive compounds, including organic acids and peptides that contribute to its health benefits (1).

Dairy-free versions of kefir can be made with coconut water, coconut milk or other sweet liquids. These will not have the same nutrient profile as dairy-based kefir.

Summary Kefir is a fermented milk drink, cultured from kefir grains. It is a rich source of calcium, protein and B vitamins.

Some microorganisms can have beneficial effects on health when ingested (3).

Known as probiotics, these microorganisms may influence health in numerous ways, aiding digestion, weight management and mental health (4, 5, 6).

Yogurt is the best known probiotic food in the Western diet, but kefir is actually a much more potent source.

Kefir grains contain up to 61 strains of bacteria and yeasts, making them a very rich and diverse probiotic source, though diversity may vary (7).

Other fermented dairy products are made from far fewer strains and don't contain any yeasts.

Summary Kefir may contain up to 61 different microorganisms, making it a much more potent source of probiotics than many other fermented dairy products.

Certain probiotics in kefir are believed to protect against infections.

This includes the probiotic Lactobacillus kefiri, which is unique to kefir.

Studies demonstrate that this probiotic can inhibit the growth of various harmful bacteria, including Salmonella, Helicobacter pylori and E. coli (8, 9).

Kefiran, a type of carbohydrate present in kefir, also has antibacterial properties (10).

Summary Kefir contains the probiotic Lactobacillus kefiri and the carbohydrate kefiran, both of which protect against harmful bacteria.

Osteoporosis is characterized by deterioration of bone tissue and is a major problem in Western countries.

It is especially common among older women and dramatically raises your risk of fractures.

Ensuring an adequate calcium intake is one of the most effective ways to improve bone health and slow the progression of osteoporosis (11).

Full-fat kefir is not only a great source of calcium but also vitamin K2 — which plays a central role in calcium metabolism. Supplementing with K2 has been shown to reduce your risk of fractures by as much as 81% (12, 13).

Recent animal studies link kefir to increased calcium absorption in bone cells. This leads to improved bone density, which should help prevent fractures (14).

Summary Kefir made from dairy is an excellent source of calcium, and full-fat dairy kefir also contains vitamin K2. These nutrients have major benefits for bone health.

Cancer is one of the world's leading causes of death.

It occurs when abnormal cells in your body grow uncontrollably, such as in a tumor.

The probiotics in fermented dairy products are believed to reduce tumor growth by stimulating your immune system. Therefore, it is possible that kefir may fight cancer (15).

This protective role has been demonstrated in several test-tube studies (16, 17).

One study found that kefir extract reduced the number of human breast cancer cells by 56%, compared to only 14% for yogurt extract (18).

Keep in mind that human studies are needed before firm conclusions can be made.

Summary Some test-tube and animal studies indicate that kefir can inhibit cancer cell growth. However, there are no current studies in people.

Probiotics such as kefir can help restore the balance of friendly bacteria in your gut.

This is why they are highly effective at treating many forms of diarrhea (19, 20).

What’s more, ample evidence suggests that probiotics and probiotic foods can alleviate many digestive problems (5).

These include irritable bowel syndrome (IBS), ulcers caused by H. pylori infection and many others (21, 22, 23, 24).

For this reason, kefir may be useful if you have problems with digestion.

Summary Probiotics like kefir can treat several forms of diarrhea. They can also lead to improvements in various digestive diseases.

Regular dairy foods contain a natural sugar called lactose.

Many people, especially adults, are unable to break down and digest lactose properly. This condition is called lactose intolerance (25).

The lactic acid bacteria in fermented dairy foods — like kefir and yogurt — turn the lactose into lactic acid, so these foods are much lower in lactose than milk.

They also contain enzymes that can help break down the lactose even further.

Therefore, kefir is generally well tolerated by people with lactose intolerance, at least compared to regular milk (26).

Keep in mind that it is possible to make kefir that is 100% lactose-free by using coconut water, fruit juice or another non-dairy beverage.

Summary Kefir is low in lactose because its lactic acid bacteria have already pre-digested the lactose. People who have lactose intolerance can often drink kefir without problems.

Allergic reactions are caused by inflammatory responses against certain foods or substances.

People with an over-sensitive immune system are more prone to allergies, which can provoke conditions like asthma.

In animal studies, kefir has been shown to suppress inflammatory responses related to allergies and asthma (27, 28).

Human studies are needed to better explore these effects.

Summary Limited evidence from animal studies suggests that drinking kefir may reduce allergic reactions.

If you are unsure about the quality of store-bought kefir, you can easily make it at home.

Combined with fresh fruit, kefir makes for a healthy and scrumptious dessert.

Kefir grains are available in some health food stores and supermarkets, as well as online.

You can also find many blog posts and videos that teach kefir production, but the process is very simple:

  • Put 1–2 tablespoons (14–28 grams) of kefir grains into a small jar. The more you use, the faster it will culture.
  • Add around 2 cups (500 ml) of milk, preferably organic or even raw. Milk from grass-fed cows is healthiest. Leave 1 inch (2.5 cm) of room at the top of the jar.
  • You can add some full-fat cream if you desire thicker kefir.
  • Put the lid on and leave it for 12–36 hours at room temperature. That's it.

Once it starts to look clumpy, it’s ready. After you gently strain out the liquid, the original kefir grains are left behind.

You can now put the grains in a new jar with some milk, and the process starts all over again.

It’s delicious, nutritious and highly sustainable.

Shop for kefir grains here.

Summary You can easily make homemade kefir using kefir grains and milk.

Kefir is a healthy, fermented food with a consistency comparable to drinkable yogurt.

This product is traditionally made from dairy milk, but plenty of non-dairy options are available.

Studies suggest that it boosts your immune system, aids in digestive problems, improves bone health and may even combat cancer.

Get started with kefir today to make the most of this tasty, sour drink.

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