Definition
A product that contains both probiotics and prebiotics is called synbiotic.1 Prebiotics are usually in the form of oligosaccharides - fructooligosaccharides (FOSs), inulin, galactooligosaccharides (GOSs) whereas probiotics are live organisms mainly of the genera Lactobacillus and Bifidobacterium.
Actions of Synbiotics
Recognition of self and non-self-antigens begins early in life. The immune responsiveness of the digestive system is significantly affected by the child's diet, state of bacterial colonization, and early exposure to potential infectious pathogens and antibiotics as well as the infant's genotype.2 It is thought that the occurrence of many diseases, both intestinal and non-intestinal such as atopy (asthma, eczema, and allergic rhinitis) or autoimmune (multiple sclerosis, type 1 diabetes mellitus, and chronic inflammatory bowel disease) is related to dysregulation or interference with the early development of the intestinal mucosal defense system.3 Toll-like receptors located in the surface membrane of T lymphocytes are triggered by nucleotides and oligosaccharides when bound to bacterial breakdown products which are important for innate and acquired immunity. Thus they play an important role in preventing gastrointestinal illness. Probiotic bacteria are believed to exert positive effects on the development of the mucosal immune system.3
Uses of Synbiotics
There is evidence that combined prebiotics and probiotics help in preventing allergic diseases in pregnant women and their infants.4 A randomized controlled trial where the addition of oligosaccharides at a concentration of 1 g/dL to preterm infant formula for 1 month (90% GOSs and 10% FOSs) increased the stool bifidobacteria counts in the oligosaccharide-supplemented group increased significantly compared with the non-supplemented group.5 Similarly, the addition of prebiotics in infant formula had led to increased counts of bifidobacteria as well as lactobacilli in their stools.6
Safety
To date, prebiotic and probiotic combinations seem to be safe for healthy infants and children. The Committee on Nutrition of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition has stated that more studies should be done to establish safety.7