The prebiotics concept was proposed by British microbiologist Gibson in 1995 as a “non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria already resident in the colon”. Specifically, it is defined as a food ingredient that has the following criteria:
It resists to host digestion (for example gastric acidity, hydrolysis by mammalian enzymes and gastrointestinal absorption).
It modulates the composition and/or activity of the gut microbiota.
It selectively stimulates the growth and/or activity of the intestinal beneficial bacteria.
It facilitates the health of the host.
In recent years, a number of fermentable carbohydrates have been reported to show a prebiotic effect. These include non-digestible oligosaccharides, polysaccharides, and dietary fibers, and some of them are known as ingredients involved in Japanese Food for Specified Health Uses (FOSHU). Various effects of prebiotics have been reported, such as the growth of beneficial bacteria in the intestine, intestinal function, enhance immune function, prevent allergic conditions, increase of mineral absorption, anti-tumor, anti-obesity, and prevention of arteriosclerosis.