Multi-omics analysis of water kefir from across the globe reveals novel insights into water kefir fermentations

Water kefir is an artisanal fermented beverage that is consumed worldwide and made from sugary water and water kefir grains. Additional fruits can be added to improve the fermentation. Water kefir grains can be reused to start new fermentations and contain mostly lactic acid bacteria, acetic acid bacteria, and yeast.

Here we will present the recent results from our multi-omics study of water kefir. We obtained 69 different water kefir grains from 21 countries and performed shotgun metagenomics sequencing, NMR metabolomics, and GC-MS volatilomics. The sequencing revealed 1) a wide diversity of species, 2) key microbes that are commonly found in water kefir, and 3) several previously unknown species in water kefir. NMR and GC-MS analysis showed a richness in metabolites and flavours, which were correlated with microbes likely to produces these compounds.

This work contributes to defining the core microbial community, lays the foundation for further research into the health benefits of water kefir, and could be used to guide the selection of species for starter cultures for scalable production of water kefir.