Kefir is a fermented beverage with a long history of medicinal uses. Recent research shows that regularly consuming kefir may improve gut health and provide additional benefits.

Jump to Key Takeaways.

How Much Kefir Should You Drink a Day?

• Daily consumption: Kefir is considered safe to consume daily. A typical serving size is one cup (8 ounces).
• Recommended intake: It is generally suggested that kefir intake be limited to one to three cups per day. Excess consumption may increase the risk of bloating, gas, and other potential side effects.
• Getting started: When trying kefir for the first time, start with a small amount and gradually increase your intake.
• How to enjoy it: Kefir can be sipped on its own, blended into smoothies, or poured over cereal or oatmeal.

What Is Kefir?

Kefir is made from kefir “grains” and milk through a process called fermentation.

• Kefir grains composition: Kefir grains are gel-like substances made from lactic acid bacteria, yeast, acetic acid bacteria, and polysaccharides (a type of carbohydrate).
• Milk used for fermentation: Kefir grains are fermented with cow’s milk, goat’s milk, or other animal milks to make a kefir beverage. However, some types of kefir are made with soy milk or other plant-based milks.
• Fermentation process: During fermentation, carbohydrates are broken down and converted into acids and alcohols. Beneficial bacteria, known as probiotics, are also naturally produced through fermentation.
• Historical use and origin: Kefir has been used medicinally for centuries and originated in the Balkans and Eastern Europe. Today, kefir is used worldwide due to its beneficial properties.

Nutritional Content of Kefir

• Macronutrients: An 8-ounce serving of low-fat plain kefir provides 9.2 grams (g) of protein (18% Daily Value, DV), 11.6 g of carbohydrates (4% DV), and 2.5 g of fat (3% DV). It’s a high-protein, low-fat dairy option.
• Micronutrients: Kefir, rich in many key micronutrients, supplies 316 milligrams (mg) of calcium (24% DV), 255 mg of phosphorus (20% DV), and 0.705 micrograms (mcg) of vitamin B12 (29% DV). These are all essential for bone health, energy, and nerve function.
• Microbial diversity in kefir: Kefir may be best known for its beneficial microbial species, including lactic acid bacteria, acetic acid bacteria, and yeasts.
• Probiotic content: Various probiotics, including Lactobacillus acidophilus, are also present in kefir.
• Variation in strains: The exact probiotics in kefir will depend on where the kefir grains came from and other factors.

How Kefir Can Boost Your Health

Drinking kefir may provide certain health benefits and promote overall well-being.

• May help balance your gut microbiome: Research suggests that kefir supports a healthy gut microbiome by increasing beneficial bacteria, which is linked to overall health benefits. Studies suggest kefir may also improve gut health and outcomes in critical illness due to gut microbiome imbalances (gut dysbiosis).
• May support immunity: Preliminary research shows that kefir may support the immune system by reducing inflammation and increasing the cytokines needed to fight infections. Antioxidants found in kefir may also help protect cells from damage.
• May help treat osteoporosis: Some studies have looked at kefir as a potential complementary treatment option for osteoporosis. Kefir reduced the loss of calcium from bones. Long-term kefir use may also increase bone mineral density (BMD), but more research is needed.
• May support heart health: Kefir possesses antioxidant and anti-inflammatory properties that may benefit heart health. Evidence also shows that kefir may indirectly improve heart health by enhancing the gut microbiome. In a small study in women with metabolic syndrome, kefir decreased blood pressure, cholesterol, and triglycerides after 12 weeks.
• May help with blood sugar maintenance: Kefir may be an effective complementary treatment for individuals with high fasting blood sugar levels. According to one meta-analysis, kefir may also help lower insulin levels, which may contribute to insulin resistance. The probiotics in kefir are thought to be responsible for these effects.

Is Kefir Safe for Me?

Although it is generally considered safe, some precautions should be taken when using kefir.

• Milk protein allergy: People with a milk protein allergy should also avoid milk-based kefir.
• Lactose intolerance: You should avoid kefir made with animal milk if lactose intolerant.
• Weakened immune system: Kefir’s probiotics are live, active microorganisms that may increase the risk of infection in people with weakened immune systems.
• Alcohol content: Due to fermentation, kefir may contain small amounts of alcohol, depending on the brand. Alcohol interacts with many medications, so you may need to wait to use kefir for at least two hours after taking them.
• Side effects: Probiotics, like the ones found in kefir, carry the risk of side effects, primarily when used in excess. Potential side effects of kefir include abdominal cramping, nausea, stool changes, gas, and taste changes.
• Medication interactions: Talk with a healthcare provider to learn how to take medications while using kefir safely.

Key Takeaways

• Recommended intake: Limit to no more than three cups (24 ounces) per day.
• Health benefits: Kefir is a fermented beverage rich in probiotics and nutrients that may benefit your gut microbiome, heart, bones, and immune system.
• Safety: Although kefir is generally considered safe, it may cause side effects and should be avoided by those with weakened immune systems.