When kefir grains are added to fresh milk, their microorganisms begin consuming available nutrients and transforming the liquid into kefir.

After fermentation, the grains can be separated using a strainer and reused to prepare another batch.

If you are not making kefir every day, the grains can generally be stored in milk in the refrigerator for a short period. Longer storage requires additional care to maintain their viability.

Kefir Nutrition Facts

The nutritional composition of kefir depends on the type of milk used, its fat content, fermentation conditions, and whether additional ingredients have been added.

Whole-milk kefir generally contains more fat and calories than low-fat kefir. However, both versions can provide valuable nutrients.

According to USDA FoodData Central, one cup (approximately 243 grams) of plain low-fat kefir provides approximately:

These values are approximate and may differ between brands and homemade preparations.

Protein

Kefir provides complete dairy protein containing essential amino acids that the body cannot produce independently.

Protein contributes to muscle maintenance, tissue repair, enzyme production, and many other physiological processes.

Drinking kefir alongside a balanced breakfast can be an easy way to increase daily protein intake.

Calcium and phosphorus

Calcium and phosphorus are essential minerals for maintaining healthy bones and teeth.

Calcium also contributes to muscle contraction, nerve signaling, and normal blood clotting. Phosphorus participates in energy metabolism and helps maintain the structure of bones and cell membranes.

B vitamins

Milk kefir contains several B vitamins, including riboflavin (vitamin B2), thiamine (vitamin B1), and vitamin B12.

These nutrients contribute to energy metabolism, red blood cell production, and normal nervous system function.

Fermentation can alter the concentrations of certain vitamins, but the exact amounts depend on the microorganisms and preparation method.

Healthy microorganisms

Perhaps the most distinctive nutritional characteristic of kefir is its microbial diversity.

Traditional kefir can contain multiple bacterial and yeast species, although the exact composition varies considerably between batches.

These microorganisms and the substances they produce are responsible for many of the potential health effects currently being investigated.

Is Kefir Low in Lactose?

One of the advantages of milk kefir is that fermentation reduces its lactose content.

During fermentation, bacteria and yeasts use lactose as a source of energy. Certain microorganisms produce enzymes that help break lactose down into simpler sugars.

Consequently, kefir often contains less lactose than ordinary milk.

This can make it easier to tolerate for people who experience bloating, gas, abdominal discomfort, or diarrhea after consuming regular dairy products.

However, kefir is not necessarily lactose-free. The remaining lactose depends on the type of milk, fermentation duration, microbial composition, and commercial processing.

People with severe lactose intolerance should start with a small serving and assess their tolerance. Those who need to avoid lactose completely should look for products specifically labeled lactose-free.

It is also important to remember that lactose intolerance and milk allergy are different conditions. People with an allergy to milk proteins should avoid conventional milk kefir, even if it has been fermented for an extended period.

Kefir vs. Yogurt: Which Is Better for Your Health?

Both kefir and yogurt are nutritious fermented dairy products that can provide beneficial microorganisms.

However, there are some important differences between them.

Traditional yogurt is generally produced using specific starter bacteria, particularly Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.

Kefir, on the other hand, is produced using a more diverse community of bacteria and yeasts.

Depending on the grains and fermentation conditions, kefir can contain numerous microbial species, including organisms that are not typically found in conventional yogurt.

This diversity is one reason researchers are interested in kefir as a potential functional food.

Another difference is consistency. Yogurt is usually thicker and eaten with a spoon, while kefir is more fluid and can be consumed as a beverage.

Kefir also undergoes yeast fermentation, which can produce small amounts of carbon dioxide and alcohol. Conventional yogurt generally does not have the same fermentation characteristics.

Neither product is automatically healthier in every situation.

For example, Greek yogurt may provide more protein per serving than some kefir products, while traditional kefir may provide a broader range of microorganisms.

The best choice depends on nutritional needs, personal taste, digestive tolerance, and the specific product.

If you want to increase probiotic food consumption, including both plain yogurt with live cultures and unsweetened kefir can provide variety.

Kefir vs. Probiotic Supplements

Probiotic supplements are available in capsules, powders, liquids, and tablets. They generally contain selected microorganisms designed to provide specific benefits.

Kefir is different because it is a whole fermented food containing microorganisms alongside protein, minerals, vitamins, and fermentation-derived compounds.

One potential advantage of traditional kefir is its microbial diversity. Instead of containing only one or two selected strains, it can contain a broader community of bacteria and yeasts.

However, this does not mean kefir is always superior to probiotic supplements.

The effectiveness of probiotics depends on the specific strain, dose, viability, and health outcome being investigated.

A well-formulated supplement containing a clinically studied strain may be more appropriate for a particular condition than an unstandardized fermented beverage.

Similarly, the microbial content of commercial kefir products can vary. Some products undergo additional processing that reduces the number of living microorganisms.

Harvard's Nutrition Source explains that heating and pasteurization after fermentation can reduce or destroy live microorganisms. Therefore, people interested in the probiotic properties of kefir should check whether the product contains live and active cultures.

The most sensible approach is to view kefir as a nutritious fermented food rather than a universal replacement for probiotics or medical treatment.

15 Potential Health Benefits of Drinking Kefir

Kefir has attracted scientific interest because it contains a combination of beneficial microorganisms, nutrients, and fermentation-derived compounds.

Some of its potential health benefits are related to digestive function and the gut microbiome, while others involve metabolic health, immune regulation, and inflammation.

It is important to remember that the strength of the evidence varies. Some benefits have been investigated in human clinical trials, whereas others are based primarily on laboratory experiments or animal research.

Here are 15 potential reasons to include kefir in a balanced diet.

1. Kefir Contains Antimicrobial Compounds That May Support Digestive Health

One of the most widely discussed benefits of kefir is its potential to support a healthy digestive system.

The human digestive tract contains trillions of microorganisms, including bacteria, fungi, and other microbes. Together, they form the gut microbiome, which plays an important role in breaking down food, producing certain vitamins, maintaining the intestinal barrier, and interacting with the immune system.

A balanced gut microbiome contains a diverse community of microorganisms. However, factors such as poor dietary habits, infections, certain medications, stress, and illness can influence the composition of this community.