Kefir alternatives, an innovative source of probiotics: Microbiological, technological, and therapeutical properties

• Water-kefir alternatives constitute a vegan alternative to milk kefir. • Water kefir grains are naturally formed via symbiotic relationship of microbial consortium. • Fermented non-dairy beverage represents a rich source of probiotic bacteria. • Potential health promoting properties of final beverage were proven. Kefir is a fermented dairy-based drink known for it's numerous health-promoting attributes. To widen kefir's beneficial health properties to a broader group of consumers, research in the area of kefir fermentations based on milk-free raw materials are necessary. Specifically, one of these represents a water kefir-like beverage, an ancient artisanal fermented drink, based on a sucrose medium with fruits, consumed practically all over the world. It's production has primarily occurred in households or on a small scale. Considering the recent market trends and scientific updates, water kefir alternatives could represent an excellent source of probiotics, supporting both healthy consumers and those who avoid dairy. In this review paper, we explained general knowledge about kefir a milk-free alternative, its origin, distribution, production process, microbial diversity and fermentation dynamics, health effects as well potential industrial processing regarding food legislation. This review also offers an updated overview of scientific studies to enhance the current understanding of this topic. The adaptation and good growth of kefir grains in different substrates could result in a wide spectra of unique products with definite sensory features and functional properties. However, the scientific community must follow the rapid progress of innovative probiotic trends, furthermore with a precise understanding of production processes under controlled conditions. Further work is still needed to bring an exact understanding of industry implementation, discussing the stable batches, shelf life and safety, resulting in a product characterized with steady quality at the industrial level.