The WHO defines Probiotics as live microorganisms which when administered in adequate amounts confer a health benefit on the host. Probiotic bacteria are extensively integrated in food production, generally the bacteria belonging to the genera Lactobacillus and Bifidobacterium, although other genera such as Escherichia, Enterococcus, Streptococcus, and Saccharomyces have also been marketed as probiotics. The health benefits most commonly associated to probiotics have been to maintain a healthy microbiota or to improve its resilience, i.e. to preserve the gut microbiota balance and the defences against pathogens. Specific probiotics may also provide other important health benefits such as desirable lactose intolerance modulation, gastrointestinal comfort (bowel function, diarrhea prevention or symptom alleviation, among others), immune response regulation, food allergy prevention, blood cholesterol reduction, vitamin synthesis or anti-carcinogenesis and anti-bacterial activities.
The term Prebiotic has been defined as a non-viable food component that confers a health benefit on the host associated with modulation of the microbiota according to the FAO. Carbohydrate substrates (e.g. dietary fiber) are widely used as prebiotics due to their capacity to promote the components of the intestinal microflora. Certain dietary components are resistant to digestive enzymes hydrolysis which avoid them to be absorbed in the gastrointestinal tract.
When probiotics and prebiotics are combined, they provide a synergistic health benefit for the host, being the product of this combination known as Synbiotics. A synbiotic is a product containing probiotic and prebiotic in which the prebiotic compound specifically favours the probiotic compound.
For food production, probiotics have been used in dairy products, however latest studies reveal that other novel probiotics are better and superior carriers for the delivery of probiotics. Food regulatory institutions such as EFSA and FDA require scientific evidence when associating a health claim to a probiotics, prebiotics or synbiotics product. The evidences need to be obtained through human interventional studies, that need to be designed following the guidance provided by these institutions. The main requirements of the study outcomes are the characterization of the strain, the identification of the health benefit for a specific target population and the demonstration of the same in a normal healthy target population.