What is a prebiotic fiber?

As Wikipedia defines it – Prebiotic is a non-digestible food ingredient that stimulate the growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial to health. They were first identified and named by Marcel Roberfroid in 1995. According to Mr. Roberfroid definition – prebiotic is a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-being and health. In short, prebiotics nourish bacteria throughout the colon.