We have been believing for years that yogurt was the best probiotic. Science is now crowning kefir
In recent months there is a dairy product that has begun to become very popular, causing traditional yogurt to begin to falter from its ‘reign’ on supermarket shelves. We are talking about kefir, a product that is increasingly you are listening much more and which is registering a boom that is driven above all by social networks that have promoted some of the benefits it can have for the digestive system. A battle. For decades, yogurt has been the undisputed leader in taking care of our intestinal flora due to the ‘good’ bacteria it has in its composition. However, at a microscopic level, the battle is completely unequal, since, while conventional yogurt usually contains between 2 and 5 bacterial strains whose effects on the intestine are transitory, kefir is a massive symbiotic consortium and offers a better long-term result. We are talking about an ecosystem that houses between 30 and 50 strains of bacteria and yeast, and here the published reviews highlight that this overwhelming microbiological diversity allows kefir to survive stomach acids and ‘settle’ in the intestine in a persistent way. In this way, the bacteria are not passing through as can happen with yogurt, but rather kefir settles and transforms the bacterial flora. And more benefits. Its level of residual lactose here is significantly lower, so the bacteria and yeast in kefir “eat” much of the sugar in the milk during its fermentation, which explains why there are clinical trials showing that lactose intolerant They digest it without having as much reflux and also with less bloating. What does science say? Here there are different sources that can be consulted that suggest that the consumption of kefir reduces some of the bacteria that colonize our mouth producing cavities and is also a proven ally in the eradication of the dreaded bacteria. Helicobacter pylori (although strict antibiotic treatment is required to eliminate it). A recent meta-analysis published in 2025 indicates that kefir also reduces markers of general inflammation and oxidative stress, which are two of the great enemies we face when we talk about harmful agents for the body if they are maintained over time. Furthermore, its ability to reduce the fasting glucose and insulin resistancemaking it a food of interest for the control of type 2 diabetes. The small print. Like everything in nutritional science, the “how much” and the “what” are critical. Here studies indicate that to obtain these metabolic and anti-inflammatory benefits, doses of between 400 and 600 milliliters daily are required, maintained constantly for periods of 4 to 12 weeks. If taken in a ‘jumping’ manner and without consistency, no results should be expected. Which one to choose. Although it may seem like it, not all kefirs are the samesince a pilot trial in healthy men showed that traditional kefir (made from real nodules) reduces LDL cholesterol and inflammatory cytokines much more than hyper-processed commercial versions. The reason is quite simple: industrialization tends to simplify microbial diversity to sterilize the product, losing along the way part of this microbiological ‘magic’ that we appreciate so much. Images | freepik In Xataka | We have been assuming for decades that “skimmed” or “0% fat” yogurt is healthier. It’s time to rethink it
