The importance of probiotics and Kefir

Kefir - youghurt for blog

Nowadays, we find ourselves having to choose between thousands of food products at the supermarket and we are careful, more and more often, about their labels and their composition.

We pay attention to sugar and fats, to preservatives, to the farming method and to all new intolerances that we discover every day, but are these the only features which we have to care about?

Most of the people don’t know that there are also some very small organisms that should be taken into account in our daily life diet: they are called micro-organism or better known as bacteria or yeast.

Although they are so small and complex, they are very important in our life, especially for the body.

So why micro-organism are so important for our body?

The long way of the food from the mouth to the anus takes place in a complex and sectioned ecosystem. In its first part, the digestive tract has a ‘sterilising’ role. In fact, starting from enzymes of the saliva, continuing with the stomach acid and the bile salt, the intestinal system reduces strongly the number of bacteria that can arrive at the colon, an intestinal segment that helps bacterial reproduction. The 50% of intestinal weight is represented by the microbial components, reaching more than 10ˆ14  bacterial cells. These microbial components are called microbiota.

Bacteria, that form intestinal microbiota, are essential to prevent a pathogenic bacterial colonization of the intestine. Thus, it is fundamental that a microbiota has a good number of ‘good’ bacteria and these have to be recognised by the immune system so that it can guarantee the stability of the composition of the intestinal bacteria population.

The most important strains of bacteria are the probiotic ones:

  • they survive the passage in the gastrointestinal tract;
  • they multiply in the intestine because they resist the acidic environment;
  • they have a positive effect on the health;
  • they are able to remain in the intestine, even though the environment is acid.

Most used strains for probiotic products are:

  • Bacillus
  • Bifidobacterium
  • Lactobacillus
  • Streptococcus
  • Saccharomyces

These stains are very important in food microbiology because they are added in some products in order to provide health benefits to people who consume them. These products are called probiotics. Initially, probiotics were made naturally by leaving milk products to ferment, but now, that they are made by food industries, starter cultures of microbes that have been isolated are added to them.

Numerous probiotic-containing foods come in the form of fermented milk products, such as yogurt, koumis, and kefir, many of which have been consumed for 100s of years.

What about Kefir?

One of the most interesting food is kefir. It has been consumed and associated with health benefits for 100s of years; originally by communities in the Caucasian mountains. The beverage itself typically has a slightly viscous texture with tart and acidic flavour. Kefir is traditionally made with cow’s milk but it can be made with milk from other sources such as goat, sheep, buffalo, or soy milk. One of the features that distinguish kefir from many other fermented dairy products is the requirement for the presence of a kefir grain in fermentation and the presence and importance of a large population of yeast. As a matter of fact, kefir contains less lactose that other product because it has some specific yeasts that feed on lactose. This makes kefir a good product also for those who have lactose intolerance. As with other fermented dairy products, kefir has been associated with a range of health benefits such as cholesterol metabolism, antimicrobial activity, tumor suppression, increased speed of wound healing, and modulation of the immune system including the alleviation of allergy and asthma.

For all these reasons kefir should be consumed, even if now you have another good reason to add five minutes to your shopping time!

About the author


I am Karolina, 23 years old and have just graduated in Food Technology in Italy. I have always been interested in food and nutrition. I love experimenting what I learn in university in my daily life, trying to improve my life style to a healthier one.


B. C. T. Bourrie, B. P. Willing and P. D. Cotter, (2018), The Microbiota and Health Promoting Characteristics of the Fermented Beverage Kefir. <
A. Farris, (2012), Microbiologia dei prodotti alimentari. CEA