There are a variety of conditions in which the use of pro-biotics has proven effective:diarrhoea with its various causes, inflammatory bowel diseases, irritable bowel disease, colon cancer chemoprevention and hepato-portal encefalopathy. The pro-biotics have shown to be a promising therapeutical alternative for the future due to their lack of side effects and convenient mode of administration. Further, the potential of other pro-biotics is awaiting validation by clinical trials.