Kombucha e kefir: características e seus benefícios à saúde

Abstract

Kombucha and kefir are low- or no-alcohol fermented beverages obtained from the fermentation of tea and milk, respectively, through the activity of symbiotic communities of bacteria and yeasts (SCOOBY for kombucha and kefir grains for kefir). Kombucha's origins date back to northeastern China, where it is valued for its detoxifying and energizing properties, while kefir has roots in the Caucasus region and is known for its health-promoting qualities. Currently, consumption of both beverages has grown globally due to the potential benefits associated with their ingestion. The objective of this study is to review the chemical and microbiological composition of kombucha and kefir, as well as the health benefits reported in scientific literature. The main components include organic acids, vitamins, polyphenols, and amino acids. In kombucha, the microbiota is composed primarily of bacteria from the genera Acetobacter and Gluconobacter, as well as yeasts such as Brettanomyces and Saccharomyces. In kefir, bacteria of the genus Lactobacillus and various yeasts predominate. Kefir is predominantly made up of bacteria of the Lactobacillus genus and various yeasts. Studies indicate antioxidant, antimicrobial, detoxifying, and hypocholesterolemic effects of both beverages. However, variability in the microbiota and fermentation conditions can influence their chemical composition and benefits. Therefore, further studies are needed to ensure greater standardization and safety of kombucha and kefir as functional beverages.