Probiotics, Prebiotics and Synbiotics - In Health Improvement by Modulating Gut Microbiota: The Concept Revisited

The microbiota of the human gastrointestinal tract plays a key role in efficient nutrient absorption and thus maintaining human health. Through the process of fermentation, gut bacteria metabolize various nutritional substrates to end products such as organic acids, vitamins, short-chain fatty acids etc. Therefore, an optimum balance is required between the intestinal microflora and its host. Under certain circumstances such as diet, medication, stress, age and general living conditions, this balance may be altered leading to the colonization of pathogenic species which is manifested as different gut disorders like inflammatory bowel disease, colonic cancer etc. Therefore, knowledge of the gut microflora and its interactions may lead to the development of dietary strategies that serve to sustain or even improve normal gastrointestinal microbiology.