AN OVERVIEW OF PROBIOTICS, PREBIOTICS AND SYNBIOTICS IN THE FUNCTIONAL FOOD CONCEPT - PERSPECTIVES AND FUTURE STRATEGIES

The functional food concept has, in recent years, moved progressively towards the development of dietary supplementation that may affect gut microbial composition and activities. The rationale behind this deriv es from a realisation that the human colon contains pathogenic, benign and possibly health promoting species. This microbiota functions in s uch a manner that the colon is the most metabolically active organ in the body-having a Very significant nutritional role. Dietary supplemen tation is a feasible route by which the large gut microbiota compositi on and activities can be modulated. Probiotics are live microbial food additions that have been in use for some time and are available in ma ny food products, primarily fermented milks. Bacteria which produce la ctic acid, that are perceived to exert beneficial properties such as i mproved lactose digestion and resistance to pathogens, are common prob iotics. Prebiotics are non-digestible food ingredients (e.g. oligosacc harides) that have a selective fermentation in the colon. Fructose oli gosaccharides are able to modify the gut flora composition in favour o f bifidobacteria. Prebiotics have been hitherto used for genus level c hanges and do not suffer the survivability difficulties that may arise with probiotics. Other strategies may exploit both technologies toget her (as synbiotics). Future perspectives that allow a more full descri ption of the gut biodiversity and accurately monitor changes in respon se to diet, will help determine the role of probiotics, prebiotics and synbiotics in health promotion. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.