Originally from the Caucasus Mountains, this ancient ferment has begun to be the subject of rigorous scientific analysis. Publications in databases such as PubMed and BMC describe it as a living symbiotic matrix, composed of a diversity of between 30 and 60 microorganisms that interact with different functions of the organism. Although studies in humans are still limited and varied, the first results suggest a possible role in digestive regulation, immune modulation and recovery of microbial balance.

Kefir is obtained from white, gelatinous granules, which concentrate a community of lactic bacteria and yeasts. During the sugar fermentation process, these granules produce compounds such as lactic acid, carbon dioxide, ethanol and other active metabolites that modify the structure of the original liquid, generating a drink rich in live microorganisms.

“It is a natural symbiosis between yeasts and bacteria that is enhanced in that shared environment“explains César Casavola, president of the Argentine Society of Nutritionist Doctors (SAMENUT).

Its origin dates back to traditional practices in the Caucasus, where milk was left to ferment in unwashed goatskin containers. Thus it was discovered that the white film generated a new, acidic drink, with a particular flavor and longer lasting. They called it kefir, from Turkish keyifwhich alludes to the feeling of well-being.

Two main varieties

Most of the studies carried out to date are in vitro or in animal models, but they suggest that regular consumption of kefir is associated with improvements in various indicators:

1. Promotes microbial diversity

bacteria like Lactobacillus kefiranofaciens, L. plantarum, L. acidophilus and yeasts like Saccharomyces cerevisiae either Kluyveromyces marxianus They help generate organic acids, enzymes and kefiran, a key polysaccharide. These elements modify the intestinal environment, reducing the pH, displacing opportunistic bacteria and acting as a prebiotic substrate.

Both variants, both milk and water, can increase bacterial diversity. Beneficial, especially after antibiotic treatments or stressful situations.

“It promotes the development of Lactobacillus and Bifidobacteriumwhile suppressing harmful microorganisms, which Helps restore a healthy intestinal environment” indicates Casavola.

In addition, a balanced microbiota improves the absorption of nutrients such as calcium and magnesium. ““This enhances the bioavailability of essential vitamins and minerals.”adds nutritionist Milagros Sympson (MN 12067).

A study in BMC Medicine showed that in critically ill patients, kefir helped reduce intestinal dysbiosis, a common imbalance in contexts of compromised health.

2. Relieves digestive symptoms

Kefir improves digestion by normalizing intestinal transit, and can be useful in cases of constipation, diarrhea or irritable bowel syndrome. “Its probiotic capacity and the reduction of colonic pH favor these effects”says Casavola.

It also produces enzymes that break down lactose, facilitating digestion in people with intolerance. The peptides and acids it generates act locally, reducing inflammation: “This strengthens the intestinal barrier, which prevents the entry of toxins or pathogens,” explains Sympson.

3. Strengthens defenses

“Its immunomodulatory effects come from both the bacteria and the compounds that are synthesized during fermentation.“, says Casavola. Among them, peptides that activate specific immune responses against infections.

Sympson emphasizes that a key part of the immune system resides in the intestineso maintaining its balance favors a better overall response.

How to prepare it

Kefir can be made at home placing the granules in a jar with milk (animal or vegetable) or sugar water. Fermentation lasts between 24 and 48 hours at room temperature. It is then strained, the granules are reused and kept refrigerated. Casavola recommends:

Regarding the quantity, with 100 to 200 ml daily It is enough to obtain proven benefits. “The most important thing is consistency, that the kefir is of good quality and is accompanied by a balanced diet,” concludes Sympson.