Millet-based probiotic beverages: a comprehensive review of nutritional potential and applications in extended and challenging environments

Purpose The rising interest in functional foods has brought millet-based probiotic beverages to the forefront as sustainable nondairy alternatives for extended and challenging environments. This study aims to examine the nutritional benefits, probiotic compatibility and practical applications in long-term preservation settings, such as space missions, military deployments and remote expeditions, while also addressing their potential use for athletes, travelers and health-conscious consumers. Design/methodology/approach A comprehensive search using keywords such as “millet-based probiotics” and “functional beverages for long voyages” was conducted across Web of Science, Scopus, PubMed and Google Scholar. This search yielded a database of 163 papers. After applying inclusion and exclusion criteria, 19 publications met the review’s requirements. An additional set of supporting literature was used to contextualize the findings, resulting in a total of 117 references. Findings Millets are nutrient-rich and possess prebiotic properties that support beneficial gut microbiota. Their fermentation compatibility makes them ideal for functional beverage development, particularly for vegan and lactose-intolerant populations. Incorporating probiotics into millet-based beverages can alleviate gastrointestinal issues, nutrient loss and immune suppression caused by prolonged travel. The worldwide market for plant-based drinks is expected to reach US$26bn in the next five years, indicating an increasing demand for dairy substitutes. Innovations in formulation and bioactivity enhancement are addressing these gaps, positioning millet-based beverages as a viable option. Originality/value This review highlights the importance of millet-based probiotic beverages in promoting dietary health and sustainability, not only for long-duration missions but also for broader consumer markets seeking plant-based, shelf-stable dietary alternatives.