Kefir — Is It Good for You? The Truth About This Fermented Super-Yogurt

If you’ve wandered past the chilled aisle in Tesco recently, you’ve probably seen bottles of Biotiful Kefir or other kefir drinkable yogurts alongside regular yogurts and smoothies. But what exactly is kefir and why has it become such a staple for gut health enthusiasts? As a doctor and BANT-certified Nutritional therapist, this is one of the most common questions I get asked.

Let’s explore what kefir really is, how it differs from yogurt, and the science-backed benefits that make it a powerful addition to a healthy diet.

What Is Kefir? Understanding Its Meaning and Origins

The word kefir comes from the Turkish “keyif”, meaning “feeling good after eating.” Originating in the Caucasus mountains centuries ago, kefir is a fermented milk drink made using kefir grains.

These "grains" are not like wheat or oats; they are a living SCOBY (Symbiotic Culture Of Bacteria and Yeasts). When added to milk, this microbe metropolis gets to work. The bacteria and yeasts in the SCOBY feed on the milk's natural sugar (lactose) and, in return, they infuse the milk with a vast diversity of probiotics, beneficial acids, vitamins, and enzymes.

This process is self-perpetuating. As the grains ferment the milk, they also grow and multiply. This means you can strain out the grains from your finished kefir and use them to start the next batch indefinitely, making it a sustainable way to create a powerful probiotic food.

The result is a tangy, slightly fizzy drink that’s thinner than yogurt — perfect for smoothies or drinking on its own.

Kefir vs Yogurt — What’s the Difference?

Although both are cultured dairy products, kefir and yogurt differ significantly in texture, taste, and microbial diversity.

Because kefir contains both bacteria and yeast, it typically has a wider range of probiotics.

In short: yogurt feeds the gut, but kefir repopulates it.

Health Benefits of Kefir

1. Supports Gut Health and Digestion

Kefir’s live cultures, such as Lactobacillus kefiri, Bifidobacterium, and beneficial yeasts, help restore balance to the gut microbiome. Studies show regular intake of fermented dairy can enhance digestion, reduce bloating, and improve tolerance to lactose.

Because kefir breaks down lactose during fermentation, it’s often better tolerated by those with mild lactose intolerance than milk or traditional yogurt.

2. Strengthens Immunity

Around 70% of our immune system resides in the gut. By supporting microbial diversity, kefir may enhance immune resilience and even inhibit the growth of harmful bacteria like Salmonella and Helicobacter pylori.

3. May Support Skin and Metabolic Health

Emerging evidence links fermented foods like kefir with reduced inflammation, improved lipid metabolism, and potentially clearer skin. Its probiotic profile may also play a role in regulating the gut-skin axis — an area of growing research in integrative medicine.

Is there such a thing as dairy free kefir?

Yes, you have some fantastic dairy-free options. I regularly recommend these to my clients.

• Plant-Based Milk Kefir: This is a direct substitute made from non-dairy milks. Coconut milk yields a wonderfully thick and creamy kefir, but versions made from oat or almond milk are also great choices.

• Water Kefir: This is a different beverage made with water kefir grains, which feed on sugar instead of lactose. It results in a light, fizzy, slightly sweet drink, more like a kombucha type drink

  
  

Is kefir good for lactose intolerance?

A final note for those with lactose intolerance: because the kefir grains consume most of the lactose in dairy milk during fermentation, many people who can't tolerate a glass of milk or standard yogurt find they can drink traditional dairy kefir without any issues.

How to Add Kefir to Your Diet

Kefir is incredibly versatile. You can enjoy it as:

• A morning kefir drink on an empty stomach to support digestion

• A base for smoothies with berries and seeds

• A replacement for milk in overnight oats or pancakes

• A salad dressing mixed with herbs, lemon, and olive oil

Aim for around 150–250 ml daily, building up gradually if you’re new to fermented foods.

Best Kefir Brands and Where to Buy in the UK

If you’re new to kefir, start with readily available, high-quality options such as:

• Biotiful Kefir – widely stocked in Tesco, Sainsbury’s, and Waitrose, made with British milk and authentic kefir cultures.

• Tesco Kefir Yogurt Drink – an accessible, affordable option in various flavours.

• Yeo Valley Kefir Yogurt – thicker, spoonable kefir-style yogurt.

Always check labels for “live cultures” and minimal added sugar to ensure you’re getting the true probiotic benefit.

Curious about how your gut affects everything from mood to hormones?

Click here to download our Free Good Gut Guide and discover evidence-based ways to support it naturally.

References

(Scientific references supporting the statements in this article. For informational use only; not a substitute for personalised medical advice.)

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2. Fiorda, F.A. et al. (2017). Microbiological, biochemical, and functional aspects of kefir. Critical Reviews in Food Science and Nutrition, 57(18), pp.3892-3903. https://pubmed.ncbi.nlm.nih.gov/28576377/

3. Rosa, D.D. et al. (2017). Milk kefir: nutritional, microbiological and health benefits. Nutrition Research Reviews, 30(1), pp.82-96. https://pubmed.ncbi.nlm.nih.gov/28222814/

4. De Oliveira Leite, A.M. et al. (2013). Microbiological and chemical characteristics of Brazilian kefir during fermentation and storage processes. Food Chemistry, 141(4), pp.2461-2469. https://www.researchgate.net/publication/236580064_Microbiological_and_chemical_characteristics_of_Brazilian_kefir_during_fermentation_and_storage_processes/fulltext/026103800cf23ae15b5fe459/Microbiological-and-chemical-characteristics-of-Brazilian-kefir-during-fermentation-and-storage-processes.pdf

5. Hempel, S. et al. (2012). Probiotics for the prevention and treatment of antibiotic-associated diarrhoea: a systematic review and meta-analysis. JAMA, 307(18), pp.1959-1969. https://pubmed.ncbi.nlm.nih.gov/22570464/

6. Marco, M.L. et al. (2021). Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology, 70, pp.147-155. https://pubmed.ncbi.nlm.nih.gov/27998788/

7. Pei, R., Martin, D.A., DiMarco, D.M. and Bolling, B.W. (2017). Evidence for the effects of yogurt on gut health and microbiota. Nutrition Reviews, 75(9), pp. 657-673. https://pubmed.ncbi.nlm.nih.gov/25875150/

8. World Gastroenterology Organisation (2023). WGO Global Guidelines: Probiotics and Prebiotics. https://www.worldgastroenterology.org/guidelines/global-guidelines/probiotics-and-prebiotics