Personalised dietary supplements adapted to the individual needs of athletes and elderly enriched with microbial propionic acid are produced in form of a powder, ready to be mixed in drinks such as orang juices. Recent studies shown that fresh and pasteurized orange juices have a positive influence on gut microbiota, exhibit selective prebiotic activity, particularly in terms of gut microbiota, by increasing Lactobacillus spp., Enterococcus spp., Bifidobacterium spp., and Clostridium spp., and reducing Enterobacteria. Besides, studies have been reported the effect of the combined use of probiotics and organic salts, such as propionic acid salts, on the in vitro inhibition of microorganisms. On the other side, the short chain fatty acid propionic acid influences the gut-mediated immune regulation of people, and reduce lipogenesis and inhibit serum cholesterol synthesis.