Microbiological Exploration of Different Types of Kefir Grains

Many studies have been published lately verifying the probiotic character of kefir grains. Most of them focused on the benefits to human health through the consumption of fermented food with kefir grains. However, the challenge is to characterize and isolate specific probiotic microorganisms involved in the kefir microbiota. The main reason for this is that the food industry prefers to apply isolated probiotic microorganisms from kefir grains rather than kefir grains in order to produce respective fermented products with added value. Thus, modern molecular techniques such as polymerase chain reaction (PCR)-based amplification, new generation sequencing (NGS) or denaturing gradient gel electrophoresis (DGGE) analyses have been applied. Furthermore, this review emphasizes the latest outcomes regarding the health benefits of the consumption of foods fermented with kefir grains and particularly the isolation of microorganisms from kefir grains worldwide, some of them exhibiting probiotic properties.