High-Throughput, Sequence-Based Analysis of the Microbiota of Greek Kefir Grains from Two Geographic Regions.

RESEARCH

backgroundKefir is a natural probiotic drink traditionally produced by milk fermentation using kefir grains. Kefir grains are composed of a complex population of bacteria and yeasts embedded in a polysaccharide-protein matrix. The geographic origin of kefir grains may largely influence their microbial composition and the associated kefir drink properties. Although the detailed bacterial composition of kefir grains from several geographic regions has been reported, to date, analogous data about the microbiome of Greek kefir are lacking. Hence, the aim of this study is to investigate the structure and the diversity of the bacterial community of Greek kefir grains. EXPERIMENTAL APPROACH: The bacterial community structure and diversity of two different kefir grains from distant geographic regions in Greece were examined RESULTS AND

conclusionsFirmicutes (a phylum that includes lactic acid bacteria) was strikingly dominant amongst the identified bacterial phyla, with over 99% of the sequences from both kefir grains classified to this phylum. At the family level, Lactobacillaceae sequences accounted for more than 98% of the operational taxonomic units (OTUs), followed by Ruminococcaceae, Lahnospiraceae, Bacteroidaceae and other bacterial families of lesser abundance. Α relatively small number of bacterial genera dominated, with NOVELTY AND SCIENTIFIC CONTRIBUTION: This is the first study to deeply explore and report on the bacterial diversity and species richness of Greek kefir.