A functional food can be defined as a food contains a component (which may or may not be a nutrient) that affects one or a limited number of functions in the body in a targeted way so as to have positive effects on health, or if it has a physiologic or psychological effect beyond the traditional nutritional effect
A huge and diverse range of bacterial species colonizes the human body. In healthy individuals, the GI tract houses more than 400 species of bacteria which are responsible for keeping harmful bacteria in check and keeping the GI tract healthy. The microbiota extend from mouth to anus and into the vaginal tract of women. They also reside on the skin. Many lines of research have demonstrated the significant role of the microbiota in human physiology. The microbiota are involved in the healthy development of the immune system, prevention of infection from pathogenic or opportunistic microbes and maintenance of intestinal barrier function. For a variety of reasons, normal native bacteria may not always perform these functions optimally, it may be due to antibiotic use, chronic diarrhea and constipation. Probiotics or Prebiotics have been shown to improve these functions.
Probiotics
Probiotics are microorganisms found naturally in foods that stimulate the growth of beneficial organisms within the gastrointestinal(GI) tract. Probiotics are widely used to prepare fermented dairy products such as yogurt or freeze-dried cultures. In the future, they may also be found in fermented vegetables and meats. Several health-related effects associated with the intake of probiotics, including alleviation of lactose intolerance and immune enhancement, have been reported in human studies. Some evidence suggests a role for probiotics in reducing the risk of rotavirus-induced diarrhea and colon cancer. The probiotics bacteria most commonly used are Lactobacillus, Bifidobacterium, Streptococus and enterococus species.
Prebiotics
Prebiotics are nondigestible food ingredients that benefit the host by selectively stimulating the growth or activity of one or a limited number of bacteria in the colon. Modification by prebiotics of the composition of the colonic microflora leads to the predominance of a few of the potentially health-promoting bacteria, especially, but not exclusively, lactobacilli and bifidobacteria. Studies involving the inulin-type fructans have generated sufficient data for thorough evaluation regarding their possible use as functional food ingredients.
Synbiotics
The combination of probiotics and prebiotics is called as a synbiotics. This combination might improve the survival of the bacteria crossing the upper part of the gastrointestinal tract, thereby enhancing their effects in the large bowel. In addition, their effects might be additive or even synergistic. It is possible to categorize the gut microbiota components on the basis of whether they exert potentially pathogenic or health promoting aspects. Lactic acid producing genera such as the bifidobacteria or lactobacilli have a long-standing association with health. These bacteria can be increased either by feeding appropriate strains as a probiotic or through the provision of prebiotic growth substrates. Probiotics and prebiotics are available commercially in many forms, including foods, dietary supplements, and clinical therapeutics with oral or non-oral ...