Int.J.Curr.Microbiol.App.Sci (2014) 3(3): 410-420 ISSN: 2319-7706 Volume 3 Number 3 (2014) pp. 410-420 http://www.ijcmas.com Review Article Probiotics, Prebiotics and Synbiotics - In Health Improvement by Modulating Gut Microbiota: The Concept Revisited Biplab Bandyopadhyay and Narayan C. Mandal* Department of Botany, Visva-Bharati, Santiniketan - 731235, West Bengal, India *Corresponding author A B S T R A C T Todays consumers are increasingly interested and conscious about their health and the food that they eat need to be healthy or even capable of preventing illness. Studies reveal that the gut health in general is a key sector for maintaining the K e y w o r d s overall health of people, whose microbiota plays a key role in metabolism and nutrient absorption. Therefore an optimum balance between the host gut and its Probiotics; microbiota is needed. Since their introduction probiotics, prebiotics and synbiotics Prebiotics; have attracted much attention for their capacity in health improvement simply by Synbiotics. maintaining the gut health. A good number of scientific laboratories now a days are in search for different prebiotics, as well as effective synbiotics preparations (i.e. combination of probiotics and prebiotics) to maintain the beneficial microbiota of the human gastrointestinal tract. Introduction The microbiota of the human different gut disorders like inflammatory gastrointestinal tract plays a key role in bowel disease, colonic cancer etc. efficient nutrient absorption and thus Therefore, knowledge of the gut maintaining human health. Through the microflora and its interactions may lead to process of fermentation, gut bacteria the development of dietary strategies that metabolize various nutritional substrates to serve to sustain or even improve normal end products such as organic acids, gastrointestinal microbiology. vitamins, short-chain fatty acids etc. Therefore, an optimum balance is required Probiotics, prebiotics and synbiotics are between the intestinal microflora and its the new concepts that have been host. Under certain circumstances such as developed to modulate the target diet, medication, stress, age and general gastrointestinal microflora balance. Since living conditions, this balance may be its introduction, the concept of probiotics, altered leading to the colonization of prebiotics and the combination of both i.e. pathogenic species which is manifested as synbiotics have attracted much attention 410 Int.J.Curr.Microbiol.App.Sci (2014) 3(3): 410-420 and different scientific laboratories have production of acids, hydrogen peroxide been screening on most efficient synbiotic and bacteriocins antagonistic to pathogen combination for maintaining sustained growth, safety, non pathogenic and non human health. carcinogenic, and Improvement of intestinal microflora (Kaur et al., 2002). Probiotics However, the mode of action of probiotics The Greek meaning of the word probiotic still remains unclear. It has been proposed is for life . Which are viable live that probiotics could maintain the healthy microorganisms when administered in intestinal microbiota through competitive adequate amounts confer a health benefit exclusion and antagonistic action against on the host (Fuller, 1989). Several pathogenic bacteria in the animal intestine lactococci, lactobacilli and bifidobacteria (Fuller, 1989). The ability of lactic acid are held to be health benefiting bacteria bacteria to inhibit the growth of various but little is known about the probiotic Gram- positive or Gram- negative bacteria mechanism of gut microbiota (Gibson and is well known. This inhibition may be due Fuller, 2000). Lactic acid bacteria or LAB to the production of organic acids such as constitute an integral part of the healthy lactic and acetic acid (Gilliland and Speck, gastrointestinal microceology and are 1977), hydrogen peroxide, bacteriocins, involved in the host metabolism bacteriocin like substances and possibly (Fernandes et al., 1987). Fermentation has biosurfactants, which are active against been specified as a mechanism of certain pathogens. On the other hand, probiotics (Gibson and Fuller, 2000). several studies have suggested that Probiotics along with other gut microbiota adhesive probiotic bacteria could prevent ferment various substrates like lactose, the attachment of pathogens and stimulate biogenic amines and allergenic their removal from the infected intestinal compounds into short chain fatty acids and tract. These antagonistic properties could other organic acids and gases (Gibson and be very useful in probiotic products. Apart Fuller, 2000; Gorbach, 1990; Jay, 2000). from this, successful probiotic bacteria LAB synthesizes enzymes, vitamins, should be able to survive gastric antioxidants and bacteriocins (Fernandes conditions and colonize the intestine, at et al., 1987; Knorr, 1998). With these least temporarily, by adhering to the properties, intestinal LAB constitutes an intestinal epithelium (Lee and Salminen, important mechanism for the metabolism 1995). Such probiotic microorganisms and detoxification of foreign substances appear to be promising candidates for the entering the body (Salminen, 1990). treatment of intestinal disorders produced by abnormal gut microflora and altered gut Probiotics - properties and mode of mucosal barrier functions (Salminen et al., action: 1996, 1998). LAB has been found to control intestinal disorders partially due to Probiotics have been suggested to have the serum antibodies IgG, and secretory IgA following properties and functions:- and IgM enhancing immune response adherence to host epithelial tissue, (Perdigon et al., 2001, Cross, 2002). acid resistance and bile tolerance, Certain strains of LAB can intermittently elimination of pathogens or reduction in translocate across the intestinal mucosa pathogenic adherence, without causing infection, thus influencing 411 Int.J.Curr.Microbiol.App.Sci (2014) 3(3): 410-420 systemic immune events (Cross, 2002). belonging to the Lactobacillus and Evidence has been presented that some Bifidobacterium genera. The most efficient lactobacilli can directly stimulate the prebiotics may also reduce or suppress immune system on the gut mucosal numbers and activities of organisms seen surface via localized GI tract lymphoid as pathogenic. For the food ingredient to cell foci (Perdigon et al., 2001). Fig. 1 be classified as a prebiotic, the following showing some of the proposed mechanism three criteria have been defined: of action of probiotics. The food ingredient must not be Influencing factors for the functionality hydrolyzed or absorbed in the stomach or of probiotics small intestine. Several factors are there, which It must be selective for beneficial technically support and influencing the commensal bacteria in the colon by function of probiotics. Among them most encouraging the growth/metabolism of the important are strain characteristics, organisms; and stability, fermentation technology, target prebiotics, viability and non viability, It will alter the microflora to a healthy microcncapsulation etc. From Fig. 2, it can composition by inducing beneficial be easily assayed how probiotic luminal/systemic effects within the host. functionality influenced by different technical factors. Any food substrate that enters the colon may be a potential prebiotic, however, Prebiotics selective fermentation is a necessary determinant. Much of the early and present Prebiotics can be defined as a non- work on prebiotics has been carried out in digestible food ingredient which Japan. The search for bifidobacteria- beneficially affects the host by selectively promoting substances began by screening stimulating the growth and/or activity of a range of carbon sources for their ability one or a limited number of bacteria in the to increase these organisms in pure colon and thus improving host health . culture. For example, Yazawa et al. (1978) The concept of prebiotics came to light screened a range of dietary carbohydrates during mid nineties of the twentieth for their ability to promote bifidobacteria century (Gibson et al., 1995). Prebiotics in comparison to other intestinal isolates. pass through the digestive system without Further studies used mixed culture, animal being broken down by the digestive models and human trials to determine the enzymes i.e. reach the large intestine in an efficacy of oligosaccharides to modulate intact form. Once these non-digestible the gut flora composition. carbohydrates pass into the intestines, they serve as a feast for the probiotic bacteria Most of the prebiotics used as food that live there. Prebiotics of proven adjuncts, such as inulin, fructo- efficacy are able to modulate the gut oligosaccharides, lactulose, dietary fiber microbiota by stimulating indigenous and gums, are derived from plants. Two of beneficial flora while inhibiting the growth the best-known prebiotics are inulin and of pathogenic bacteria therein. Preferred trans-galactooligosaccharides (TOS) occur target organisms for prebiotics are species naturally in foods such as garlic, onions, 412 Int.J.Curr.Microbiol.App.Sci (2014) 3(3): 410-420 leeks, shallots, Asparagus, spinach, (1 2) linear molecules. In any Jerusalem artichokes, chicory, peas, beans, circumstances that justify identification of lentils, oats and bananas. The resistance of the oligomers vs. polymers, the terms inulin to digestive processes has been oligofructose and inulin can be used, extensively studied by applying both in respectively. Though inulin hydrolysate vitro and