Kefir: What are the real benefits of this trendy fermented drink?

We see it everywhere on social media: kefir, the fermented drink touted as a miracle cure for digestion, skin, and metabolism. But what do the scientific studies actually say? RMC takes stock.

Kefir is a fermented drink obtained from kefir grains, small white balls containing a mixture of lactic acid bacteria and yeasts. There are two main varieties:

• Milk kefir, with a slightly acidic taste, similar to buttermilk
• Fruit kefir, prepared with water, sugar and fruit, is fresher and more sparkling.

This drink, consumed for centuries in the Caucasus and the Middle East, is making a strong comeback today, driven by social media and “healthy” trends.

Many internet users praise its effects on digestion, metabolism, and even weight loss. In reality, the scientific evidence remains limited.

Kefir contains probiotics, microorganisms believed to support intestinal flora. A study of 22 people with metabolic syndrome observed a moderate decrease in fasting insulin and improved insulin sensitivity after 12 weeks of consumption.

But be careful:

• the differences are not significant compared to the control milk,
• and no clear effects have been demonstrated on weight, fat, or inflammatory markers.

In short: kefir can slightly modify the microbiota, but its overall impact on health remains modest.

On TikTok, some claim that drinking kefir makes skin clearer or hair stronger. However, there are no scientific studies to support these claims. Probiotics have a recognized effect on the digestive system, but not on the skin or scalp. These claims are therefore more marketing than medical.

Kefir remains an attractive alternative to soda, especially when prepared at home. However, caution is advised: in Europe, a drink can contain up to 1.2% alcohol without it being indicated on the label.

Milk kefir contains very little alcohol, but fruit kefir undergoes a light alcoholic fermentation that can reach 1%. Therefore, consume in moderation, especially for children and pregnant women. Kefir is a generally healthy drink, but by no means miraculous. Good for variety, yes. For healing or beautifying, no.