What Is Kefir And Is It Good For You?


By Doug Cook, RDN

Kefir (pronounced ‘kuh-feer’) is a cultured/fermented dairy product that originated with shepherds of the North Caucasus  region.

They discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage (because the fresh raw milk was rich in probiotic bacteria and yeasts).

Modern Kefir

Nowadays, kefir is the result of mixing ‘kefir grains’, composed of a complex structure of bacteria and yeasts with proteins, lipids and sugars, with milk. The microorganisms ferment the naturally-occurring milk sugar, lactose, into a sour, carbonated, beverage with a consistency similar to thin yogurt.

The taste of kefir is unmistakable; it has an ever so slightly malt flavour with an effervescent feel, not dissimilar to buttermilk. I attended a kefir workshop hosted by the Toronto chapter of the Weston A Price Foundation and learned how to make kefir at home using fresh kefir grains, which, look a lot like cauliflower.

I carefully took my sample home in small mason jar with a little milk, eager to to start to make my own batch.

It’s important to note that kefir grains are live bacteria & yeasts as opposed to the starter kits you get at the health food store which are freeze dried. Taking care of kefir grains is easy; simply place them in milk so that they have “food” and are able to grow. This is what I took home and what is currently living in a glass jar of milk, in my fridge.

What, or who, is living in that clump of kefir grains?

Typically kefir grains will contain the following micro-organisms, although there is some variation between batches:

  • Lactococcous lactis lactis
  • Lactococcous lactis cremoris
  • Lactococcous lactis diacetylactis
  • Leuconostoc mesenteroides cermoris
  • Lactobacillus kefyr thermophilic
  • Klyveromyces marxianus marxianus
  • Saccaromyces unisporis
  • Acetobacter species and Streptococcus species
  • and more…..

Kefir made at home would vary greatly in the concentration and type of bacteria & yeast that it contains. Therefore its impossible to guarantee any therapeutic effect like preventing antibiotic-associated diarrhea etc.

A true probiotic is one that has been clinically tested to be effective such as preventing C. difficile, antibiotic associated diarrhea, travellers’ diarrhea etc.

Nevertheless, kefir is a highly nutritious dairy product and is a good source of protein and calcium, a moderate source of magnesium, B2, B12 and is low in carbohydrate [lactose].

There is some research to show that a good quality kefir, made with live grains, and those found in products made with strict quality assurance, can help.

These better quality (non pasteurized kefir products) can support the digestive tract and increase the amount of bacteria. as long as the kefir is being consumed. They will only contribute to maintaining a healthy digestive tract if part of your regular diet; they don’t permanently colonize your gut.

Kefir is not yogurt

Kefir and yogurt are both fermented dairy products; therefore, this may lead some to assume that both kefir and yogurt offer the same health benefits. However, this is not the case as kefir contains different types of beneficial bacteria that yogurt does not.

Fresh kefir also contains both significantly more bacteria and greater diversity of micro-organisms than yogurt.

Yogurt is produced by the action of two specific bacteria: lactobacillus bulgaricus streptococcus thermophilus. Once the milk has been fermented, the amount of live bacteria is negligible, and often, food companies will heat pasteurize the yogurt afterwards to extend the shelf life. Yogurt has not been shown to have any beneficial probiotic effect beyond being an easily digestible dairy food.

How to use kefir

As part of a healthy diet, kefir can be a valuable addition and can be easily incorporated into your daily fare. Kefir, whether it’s homemade like mine using live kefir grains, or a quality store bought product, can be used almost anywhere you’d use milk: cereal, smoothies, as a beverage straight up in a glass, and in baking [although the heat will kill off most of the bacteria and yeast].

Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, mental health.  Follow him on FacebookInstagram and Twitter.