Probiotics are living micro-organisms that are active in sufficient numbers in the colon and have a positive effect on our health. The special feature of probiotics is that they survive attacks from gastric and bile acids and so reach the colon safely. Probiotic bacteria mainly belong to the Lactobacillus and Bifidobacterium genera.
Source: Gibson GR & Roberfroid MB (1995). Dietary modulation of the human colonic micro-biota: Introducing the concept of prebiotics, Journal of Nutrition, Vol. 125, No. 6, 1401–1412
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