In recent years, the health food industry has been experiencing a real boom in fermented beverages. Supermarket shelves are full of various bottles of kombucha, craft kefir and ayran, which marketers position as a universal elixir for digestive health. We are promised an instant improvement in immunity, perfect digestion and detoxification.

Modern 4P medicine (personalized, predictive, preventive, patient-centered) proves that the human body is a complex "superorganism" inhabited by about 38 trillion bacterial cells. This giant ecosystem, our microbiome, regulates almost all life processes: from the formation of immunity to weight control and mood through the "gut-brain" axis.