Probiotics in carp fish nutrition

Uncontrolled use of antibiotics in aquaculture caused the appearance and spreading of pathogens resistance to antibiotics, what consequently drove up to the necesity of finding new technologies for protecting aquatic organisms from pathogens. Probiotics are aimed to reduce antibiotics application, and furthermore they have an important role not only in disease prevention but also in efficiency of food utilization and improvement of production parameters. Carp fish species are economically most significant in Republic of Serbia, therefore this work summarizes the results of previous studies of antibiotics application in this kind in particular. There is also pointed out to numerous harmful side effects of antibiotics use in aquaculture, and described the previous results of investigations on mechanism of probiotics effects and specificity of their use in this field as well. Beside this, there are summarized the results that show positive influence of probiotics in cyprinides nutrition on production performance, haematological parameters, course of experimental infection, activity of digestive enzymes. Special attention is paid to criteria for proper selection of probiotics in cyprinides production. [Projekat Ministarstva nauke Republike Srbije, br. TP 31011: Uticaj kvaliteta komponenata u ishrani ciprinida na kvalitet mesa, gubitke i ekonomičnost proizvodnje

Probiotics – myth or reality?

Spoznaja da nisu sve bakterije nužno patogene, već naprotiv, neke od njih posjeduju brojne poželjne učinke na ljudsko zdravlje, dovodi do formiranja termina probiotik. No, kako bi bakterijski sojevi bili definirani kao probiotici moraju ispuniti određene uvjete, a potrebno je i točno odrediti djelotvorne učinke svakog soja. Kako bi probiotici mogli vršiti svoju funkciju moraju preživjeti prolazak kroz gastrointestinalni trakt čovjeka te pristići u debelo crijevo u dovoljnom broju da utječu na ekologiju i metabolizam bakterija u tom području. Faktori s kojima se susreću tijekom prolaska kroz gastrointestinalni trakt uključuju: otpornost na želučanu kiselinu i žučne soli, sposobnost prianjanja za epitelne stanice crijeva, modulaciju domaćinovog imunosnog odgovora i antimikrobnu aktivnost probiotika. Potencijalna korist probiotika za ljudsko zdravlje obuhvaća modulaciju mukoznog imunosnog odgovora te prevenciju i liječenje nekih crijevnih upalnih poremećaja, a probiotici koji svoj učinak ostvaruju upravljanjem mukoznim imunosnim sustavom nazivaju se imunobiotici. Osim modulacije mukoznog imunosnog sustava probiotici mogu djelovati i izravno na crijevnu mikrofloru, putem antimikrobne aktivnosti. Neki to rade izlučivanjem nespecifičnih antimikrobnih supstanci, poput masnih kiselina kratkih lanaca ili vodikovog peroksida, dok ostali proizvode toksine sa uskim rasponom ubijanja, odnosno bakteriocine.A notion that not all bacteria are necessarily pathogenic; that, in fact, some of them carry numerous positive effects on human health led to forming the term probiotic. For a bacteria strain to be labeled probiotic, it must meet certain requirements, as well as have its positive effects correctly determined. For probiotics to fulfill their function they need to survive the gastrointestinal tract and arrive at the colon in sufficient numbers to affect the bacterial ecology and metabolism in that area. Relevant factors when traversing the tract include: stomach acid and bile acid resistance, ability to adhere to colon’s epithelial cells, modulation of host’s immunity response and probiotic’s antimicrobial activity. Potential human health benefits include modulation of mucosal immunity response, prevention and treatment of certain inflammatory bowel disorders, provided by probiotics labeled immunobiotics. Other than mucosal immunity response modulation, probiotics can directly affect the colon’s microflora by antimicrobial activity. Some do so by secreting nonspecific antimicrobial substances, such as short-chain fatty acids or hydrogen peroxide, while others produce toxins with very narrow killing ranges, such as bacteriocins

PROBIOTICI E TERAPIA CONVENZIONALE: NUOVE FRONTIERE NELLA GESTIONE DELLE MANIFESTAZIONI ARTICOLARI DELLE MALATTIE INFIAMMATORIE INTESTINALI (IBD)

Summary: This work reports a clinical trial performed at palermo University Hospital "paolo Giaccone". From January 2004 to December 2011, 79 patients were enrolled (40 men and 39 women). All patients suffered from Inflammatory Bowel Disease (IBD) and were subjected to orthopedic consultation at the institute of Orthopaedics, University Hospital of palermo, for arthropathy to IBD. The patients were divided into two groups (A and B) and dealt with different therapies for the resolution of the inflammatory picture of the colonic mucosa and the treatment of the extraintestinal articular manifestations. Group A was treated with drug therapy: Diclofenac (75 mg im/ day for 10 days9 and Mesalazine (800 mg gastro-resistant tabletes, one tablet twice a day in mild forms, and one tablet three times per day in moderate forms). In group B, in addition to the previous treatment protocol, two probiotic mixture were added in a time of two weeks: in the first week, twice a day, one capsule containing mixture of Enterococcus faecium and saccharomices boluard was administered, with the main purpose to mitigate the intestinal inflammation; in the second week, twice a day too, one capsule containing a mixture of lactobacillus salivarius and lactobacillus acidophilus was administered, with the main purpose to mitigate the intestinal inflammation, in the second week, twice a day too, one capsule containing a mixture of lactobacillus salivarius and lactobacillus acidophilus was administered, with the aim to promote the restoration of a normal intestinal microenvironment. The attenuation of intestinal inflammation, improved by the presence of probiotics, could have important effects on the articular manifestations, resulting in a significant improvement of the arthropathy. All patients were evaluated with the Harvey-Bradshaw Index. Both Crohn Disease and Ulcerative Cholitis diagnosis was made with clinical, laboratory, endoscopic and instrumental tests; the degree of disease activity was evaluated using the criteria of Truelove and witts. The WOMAC-Score (Western Ontario Mcmaster) was used in our study to investigate the degree of articular involvement of the patients. The data were statistically evaluated and these are shown that the B group of patients treated with conventional therapy + probiotic mixture had a better resolution of the clinical and of this post-treatment parameters: WOMAC score, ESR, CRP and white blood cells; and also the B group of patients have a better response to standard therapy compared with patients who did not receive the probiotic with a remarkable statistic significance (p>0,0001)

Probiotic Concept - Probiotics as Food Supplements and Probiotics as Biotherapeutics

Svjetska zdravstvena kriza, posebice u liječenju infektivnih bolesti zbog alarmantnog stanja s antibiotičkom rezistencijom te niz kroničnih bolesti koje ugrožavaju ljudsko zdravlje, proizvelo je situaciju za uspostavljanje koncepta funkcionalne hrane još 1980. godine, u Japanu. Dakle, hrana je funkcionalna ako sadrži sastojke koji pozitivno djeluju na jednu ili više ciljanih funkcija u tijelu. Ciljno mjesto djelovanja probiotika, prebiotika, odnosno sinbiotika, kao funkcionalnih dodataka hrani, je gastrointestinalni sustav. Taj sustav je najveći imuno organ u ljudskom organizmu s aktivnom površinom od oko 300 m2, a sadrži vrlo kompleksnu mikrobnu populaciju (crijevnu mikrofloru) ukupne mase od 1,2 kg. Ovako golema mikrobna biomasa i njezina metabolizamska aktivnost nisu bez utjecaja, mogu imati pozitivne i negativne učinke na ljudsko zdravlje. Ravnoteža ovog mikrobnog sustava je dinamična i može se poremetiti pod utjecajem starenja, liječenja, stresa, prehrane i drugih čimbenika iz okoliša. Probiotički, prebiotički, odnosno sinbiotički koncept podrazumijeva ponovno uspostavljanje ravnoteže crijevne mikroflore i usmjeravanje njenog metabolizma u proizvodnju metabolita korisnih za zdravlje. Obećavajući rezultati s prvom generacijom probiotika nude novu generaciju probiotika (živih lijekova) gdje će se kombinacija različitih probiotičkih sojeva s komplementarnim djelovanjem koristiti u liječenju različitih gastrointestinalnih i urogenitalnih bolesti ili će se koristiti kao vektori za vakcine, imunoglobuline i druge terapijske proteine. Rad se bazira na prikazu objavljenih rezultata znanstvenih istraživanja koja su provedena u Laboratoriju za tehnologiju antibiotika, enzima, probiotika i starter kultura na Prehrambeno-biotehnološkom fakultetu Sveučilišta u Zagrebu.World health crises, especially in a prevention of infective diseases and as result of the wide spread of antibiotic resistance and the number of chronic diseases that disturb human health, has lead, already in the 1980s, to the establishment of the functional food concept (FOSHU Food for specifi ed health use) in Japan. Hence, the food is defi ned as functional “ if it contains a food component (whether a nutrient or not) which affects one or a limited number of function(s) in the body in a targeted way so as to have positive effects”. Target place of action of probiotics, prebiotics or synbiotics, as functional food supplements, is gastrointestinal tract. Gastrointestinal tract represents the largest immune organ in our body with an active space of approximately 300 m2 and it contains a complex microbial ecosystem (gut microfl ora) with a total weight of 1.2 kg. Such a complex microbial biomass and it metabolic activity can have positive but also negative infl uence on human health. The balance of gut microfl ora is dynamic and could be disturbed by the infl uence of different factors like ageing processes, healing, stress, diet, and many other environmental factors. Probiotic, prebiotic and synbiotic concept imply the reestablishment of the disturbed gut microfl ora and direction of it metabolism to the production of bioactive metabolites benefi cial for health. The promising results of a first generation of probiotics offer new generation of probiotics (biotherapeutics) that will often contain mixture of probiotic strains with complementary characteristics, tailormade for different gastrointestinal and urogenital diseases, or as delivery systems for vaccines, immunoglobulins and other protein based therapies. In this paper the review of the published results of the investigations, performed in the Laboratory of Antibiotic, Enzyme, Probiotic and Starter Culture Technology at Faculty of Food Technology and Biotechnology University of Zagreb, are presented

Probiotici i prebiotici kod arterijske hipertenzije

There is growing evidence that a disturbed microbiota, a complex ecosystem, is associated with the development of numerous diseases, including arterial hypertension. This complex cardiovascular disease is the result of not sufficiently clear role that genetic and environmental factors play in it. Not only does the treatment of hypertension include a drug therapy, but also it includes a variety of non-pharmacological measures based on dietary intervention. Probiotics and prebiotics are besides the nutrition the most commonly used substances that are aimed at maintaining a healthy microbiome or restoring the balance in case of disturbed bacterial homeostasis in disease. Although many studies have confirmed the effects of an imbalance in the gut microbiota (dysbiosis) in the last decade, the benefits of dietary intervention with probiotics in people with hypertension need to be supported by stronger evidence and further clinical trials in order to be ultimately confirmed.Sve je više dokaza da je narušen sustav ljudske mikrobiote, kompleksnog eko sistema, povezan s patogenezom brojnih bolesti, među ostalim i arterijske hipertenzije (AH). Ova kompleksna kardiovaskularna bolest rezultat je još uvijek nepotpuno jasne uloge genetskih i okolišnih čimbenika. Liječenje AH pored medikamentnog liječenja obuhvaća i višestruke nefarmakološke mjere čiji temelj predstavljaju dijetalne intervencije. Najčešće korištene tvari kojima se nastoji održati zdrav mikrobiom ili uspostaviti ravnoteža pri poremećenoj bakterijskoj homeostazi u bolesti su, osim prehrane, probiotici i prebiotici. Iako mnoga istraživanja u zadnjem desetljeću potvrđuju učinak disbalansa crijevne mikrobiote (tzv. disbioze), za definitivnu potvrdu dobrobiti dijetalne intervencije probioticima kod osoba s AH, potrebni su snažniji dokazi te daljnja klinička istraživanja

STUDIO DEL TESSUTO LINFOIDE ASSOCIATO ALL’INTESTINO (GALT) PER APPLICAZIONI BIOTECNOLOGICHE IN ACQUICOLTURA DI SPECIE ITTICHE

The mucosal surfaces represent a major interface between the organism and the external environment. Although evidence has accumulated for the existence of mucosal immunity mechanisms in fish, as it would be expected for animals living in a pathogen-rich aquatic environment, this field of research is still poorly explored. The mucosae of fish skin, gills and gut are protected by both humoral and cellular mechanisms (Peleteiro & Richards, 1985; Hart et al., 1988; Rowley et al., 1988; Roberts, 1989). Leucocytes occur in all parts of the teleost digestive system, most extensively in the intestine, where lymphocytes, plasma cells, granulocytes and macrophages are present in and under the epithelium. Although large lymphoid centres are lacking, many lymphoid cells, either scattered or in small groups, were reported to be present in the epithelium and lamina propria (Zapata, 1979; Davina et al., 1980; Temkin & McMillan, 1986; Hart et al., 1988). Various studies indicated that regional differences occur in the organisation of the gut-associated lymphoid tissue (GALT) at different levels of the digestive tract, possibly reflecting specialised immunological functions. Uptake and transport of antigens have been shown to occur mainly in the second gut segment of carp, Cyprinus carpio L. (Rombout et al., 1985, 1986; Rombout & Van den Berg, 1989), and trout, Oncorhynchus mykiss (Georgopoulou et al., 1986), where antigens are transported from the lumen to large intraepithelial macrophages, which can exert an antigen-presenting function (Rombout et al., 1985, 1986). These findings demonstrated the high immunological relevance of the fish GALT. The study of GALT cellular components, their specific location, morphological and functional characteristics is crucial to understand the role of GALT within the whole fish immune system. The main objective of this thesis was to improve the knowledge about the cell-mediated intestinal immunity in two fish species of great economic importance: the European sea bass (Dicentrarchus labrax L.) and the common carp (Cyprinus carpio L.). Special attention has been devoted to cell-mediated cytotoxic response, among defence mechanisms against foreign (allogeneic or xenogeneic) or altered (e.g. virus-infected) cells. In higher vertebrates, cell-mediated cytotoxicity (CMC) is exerted by NK cells or CTLs, respectively, as the cellular parts of the innate or the adaptive immune defence. NK cell killing is triggered by invariant receptors that recognize molecular patterns on infected cell surfaces. CTLs specifically recognize and kill cells that present peptides derived from antigens synthesized intracellularly (e.g. viral proteins) with major histocompatibility complex (MHC) class I molecules on the cell surface. Recognition of the MHC/peptide complex is mediated by the T cell receptor (TCR). During the last years, MHC class I-restricted effector/target cell recognition systems have been established in some fish species, but the abovementioned mechanisms have been shown in principle but not fully proven. A main problem is that cells performing CMC in fish are still poorly characterized due to the lack of appropriate tools for the specific recognition of lymphocyte populations. Cell-specific markers are indispensable for cell identification, especially of T lymphocyte subpopulations, which seem to have a key role in this type of response. The panel of available monoclonal antibodies (mAb) to fish leucocytes is still very limited: an anti-thymocyte mAb (DLT15) reacting with peripheral T cell populations of sea bass (Scapigliati et al., 1995), a mAb (WCL9) reacting with early T cells of carp (Rombout et al., 1997), a mAb against carp intestinal T cells (WCL38) (Rombout et al., 1998) and a mAb reacting with a T cell population in channel catfish (Passer et al., 1996). In addition, a mAb (5C6) raised against channel catfish, Ictalurus punctatus, non-specific cytotoxic cells (NCC; Ig- lymphoid cells), apparently reacting with NK cells in a variety of vertebrate species (Evans et al., 1988; Evans and Jaso-Friedman, 1992). The existence of anti-T cells appropriate MAbs in carp and sea bass has been a main reason to study here these two fish species. Moreover, homologous sequences of TcRβ, CD8α, CD4 and MHCII-β, four important genes involved in T cell function, became recently available for sea bass. These sequences were used to perform quantitative RT-PCRs and in situ hybridization studies.The results obtained with these molecular techniques, together with those obtained by the use of cell-specific mAbs (FACS analysis and immunohistochemistry), suggested that in sea bass and carp GALT mainly consists of T cells and likely exerts cytotoxic activity (Rombout et al., 1998; Guerra, PhD Tesis 2008). The aim of this thesis was to confirm these hypotheses with functional tests. In fish, allogeneic and xenogeneic cells represent standard model targets of cytotoxic effector cells.Specific and non-specific cytotoxicity assays and different immunisation protocols were developed for the carp and the sea bass using a Epithelioma papulosum cyprini (EPC) carp cell line, a continuous embryonic cell line from European sea bass (DLEC) and a human erythroleukemic cell line (K562) as target cells, and the release of lactate dehydrogenase (LDH) as read out system (Cytotox 96® kit PROMEGA).Non-specific cytotoxicity against EPC was not observed in non-immune specimens, while carp immunised i.p. with EPC clearly showed specific killing by effector cells [purified lymphocytes (90-95% by FACS) by discontinuous Percoll gradient, density 1,02-1,06] present in kidney, spleen and blood, but not in the gut. These results agree with a previous study (Companjen et al.,2006). Otherwise, non-specific cytotoxicity against K562 cells (xenogeneic) was observed in non-immune specimens, ascribed to purified lymphocytes from head kidney, spleen and PBL (negligible in lymphocytes from the intestine). Immunisation with K562 evoked a net increase in cytotoxic responses against the K562 cells, compared with PBS treated controls. The effect was registered in systemic organs (head kidney and spleen), but especially in the intestine. The anal immunisation protocol with lysed cells was the most effective in increasing the CMC against xenogeneic target cells of both systemic and mucosal organs. Taken together, these data can lead to various conclusions: 1) carp apparently lacks non-specific allogeneic cytotoxicity, 2) non-specific xenogeneic cytotoxicity is only systemic (e.g. in head kidney, spleen and PBL), 3) specific cytotoxicity can be induced in kidney and spleen cells following i.p. immunisation with allogeneic cells (EPC), 4) cell-mediated cytotoxic response against xenogeneic cells (K562) can be increased in the intestine and systemic organs by immunisation (anal or i.p).In the sea bass, GALT immunohistochemical analysis preceded the study of CMC. For this study, a polyclonal antibody (A0452 DAKO) raised in rabbit against huma n CD3 ε was used. This pAb has been shown to react wi t h blo o d leuco c y t e s in snapp e r, Pagrus auratus (Coo k et al., 2001), and Japanese flo u n d e r, Paralichthys olivaceus (Park et al. 2005). Th is antib o d y also detects CD3 ε in vari o u s mam ma l s (Jones et al., 1993) and the amp hibian Xenopus laevis (Göbel et al. 2000), illu strating the conser vation of the epito p e. The demonstration of reactivity of this antibody towards CD3 ε in snap per and flounder has identified a candidate antibody for the detection of T cells in other teleost species. Th is antib o d y showed cross-reactivity with lymphocytes of sea bass. The localization and distribution of CD3+ cells in the sea bass intestinal mucosa are here shown for the first time. The comparison between the data obtained with the mAb DLT15 and those obtained with the anti-CD3 ε pA b showed that the majority of sea bass intra-epithelial lymphocytes (IEL) is a CD3ε – population. Otherwise, most IEL of the carp seem to be CD3ε +. Further studies are needed to assess the putative occurrence of T cell subpopulations in the intestinal mucosa , and to explain the observed species differences.In sea bass, lymphocytes isolated from head kidney, spleen and gut exhibited non-specific cytotoxicity against DLEC (allogeneic cell line). The highest activity was observed in intestinal lymphocytes, although significant responses were also seen in spleen and head kidney lymphocytes. Also the non-specific cytotoxicity against K562 (xenogeneic cell line) was significant in lymphocytes purified from head kidney, spleen, blood, gut and gills. These results suggest a wide occurrence of xeno-reactive cells in sea bass organs, that in carp were localized only in systemic compartments. Following anal immunisation with K562, cell-mediated citotoxicity against xenogeneic targets decreased significantly both in systemic and mucosal organs, compared with controls. Therefore it can be hypothesised that this decrease may be due to induction of tolerance, but further studies are needed to test this hypothesis. Such informations would improve the efficacy of oral vaccination in sea bass and optimize the antigen delivery to the appropriate cellular targets. A very promising procedure to improve the mucosal immune defence mechanisms is the dietary administration of probiotics, that appeared as a effective tool for the control of pathogen outbreaks in fish farms. Many authors have repo r te d increase d disease resista n ce in fish fed bacter ia-supplemented diets (Bly et al., 1997; Robertson et al., 2000; Spanggaar d et al., 2001; Raid a et al., 2003). In this thesis we investigated the effects of the oral administration of heat-inactivated Lactobacillus delbrüeckii ssp. lactis and Bacillus subtilis, individually or combined, on immune responses, both systemically and locally in the gut, in a further marine teleost species, the gilthead seabream (Sparus aurata L.). In a first experiment, seabream (65 g) were fed for 3 weeks different diets supplemented with 1 x 107 CFU g-1 Lactobacillus, 1 x 107 CFU g-1 Bacillus, or 0.5 x 107 CFU g-1 Lactobacillus plus 0.5 x 107 CFU g-1 Bacillus. Controls were fed non-supplemented diet. Six fish per group were sampled at the end of the trial and some humoral and cellular systemic innate immune parameters were evaluated. Feeding the mixture of the two killed bacteria species significantly increased natural complement , serum peroxidase and phagocytic activities compared with controls. In a second experiment, juvenile seabream (13 g) were fed for 3 weeks the same experimental diets and total serum IgM and numbers of gut Ig M + cells and acido philic granulocytes were evaluated. All these parameters were significantly higher in the multispecies probiotic group compared to monospecies and control fed groups. The results of the present study indicated that oral administration of heat-inactivated probiotics has stimulatory effects, both local and systemic , on the immune system of the gilthead seabream. The multispecies formulation was more effective than any of the sing le-bacteria experimental diets. These results suggest that, as in humans, the appropriate design of multispecies probiotics, including inactivated cells, can have synergistic positive effects on fish health

Il microbiota intestinale: nuovo strumento di terapia?

Il microbiota intestinale ha assunto in questi anni una grande importanza, poiché vari studi e vari esperimenti dichiarano la sua correlazione con il sistema immunitario e con il mantenimento dell’omeostasi intestinale, nonché con la regolazione dell’integrità dell’epitelio e della motilità intestinale (peristalsi). Nel momento in cui va a mancare o viene perturbato il giusto equilibrio intestinale, si possono creare squilibri che portano ad un’invasione dei tessuti da parte di alcune specie microbiche e come conseguenza di questa disbiosi si può avere l’istaurarsi di una nuova malattia, tenendo conto che il microbiota stesso cambia a seconda della porzione del tratto digerente presa in considerazione. Tra i componenti del microbiota umano troviamo probiotici, commensali, patogeni opportunisti; oltre a questi di assoluta importanza vi sono anche i prebiotici che non sono altro che alimenti non digeribili che stimolano la crescita dei batteri facenti parte della flora batterica. Questo microbiota intestinale è di notevole importanza in quanto risulta anche correlato a diverse malattie, sia intestinali che extra-intestinali. The intestinal microbiota has become in recent years a great importance because various studies and various experiments declare its correlation with the immune system and maintaining intestinal homeostasis, as well as the integrity of the epithelium and regulation of intestinal motility (peristalsis). When goes missing or gets disrupted the proper intestinal balance, is possible that this creates imbalances that lead to an invasion of tissues by certain microbial species and as a result of this dysbiosis can have a new disease, taking into account that the same microbiota changes depending on the portion of the digestive tract regarded. Among the components of the gut flora are probiotics, diners, opportunistic pathogens; in addition to these absolute importance, there are also prebiotics, that are non-digestible foods that stimulate the growth of the bacteria which are part of the bacterial flora. This intestinal microbiota is so important also because it is related to various diseases, both intestinal and extra-intestinal

ANTIMIKROBNA REZISTENCIJA BAKTERIJA MLIJECNE KISELINE IZ HRANE

Bakterije mlijecne kiseline imaju veliko znacenje u higijeni i tehnologiji hrane. Poznati su njihovi pozitivni ucinci na zdravlje ljudi (zdravstvene tvrdnje; probiotici), zatim antimikrobni ucinci prema štetnim bakterijama (sintetiziranjem antimikrobnih tvari; organskih kiselina, bakteriocina i dr.), te tehnološke prednosti koje se koriste u razvoju proizvoda (senzorna svojstva). S druge strane, novija saznanja upozoravaju na rizik zbog otpornosti «bezopasnih» bakterija mlijecne kiseline na antibiotike, posebno zbog horizontalnog prijenosa rezistencije na patogene bakterije. U procjeni sigurnosti potencijalnih starter i probiotskih kultura nezaobilazan je postupak detekcije prenosivih gena odgovornih za antimikrobnu rezistenciju

Intestinal microbiota composition in patients with gastrointestinal disorders

U ljudskom probavnom sustavu nalazi se više od 100 trilijuna mikroorganizama koji čine crijevnu mikrobiotu što je 10 puta više nego broj svih ljudskih stanica u organizmu. Uspostava i razvoj ekološkog sustava crijevne mikrobiote počinje s rođenjem, a uspostavljena crijevna mikroflora tijekom života je relativno stabilna, no podloţna utjecajima egzogenih i endogenih faktora (prehrana, korištenje lijekova, bolesti, starenje). Sastav crijevne mikrobiote je specifičan za svaku osobu i teško je definirati što je zdrava mikrobiota. Crijevna mikrobiota ima značajnu ulogu u čovjekom zdravlju i bolesti. Vaţnost crijevne mikrobiote se očituje kroz njihove utjecaje na čovjekovu fiziologiju, metabolizam, prehranu i imunosnu funkciju. Disbioza ili poremećaj crijevne mikroflore je pojam koji označava narušavane prirodne ravnoteže mikroorganizama u probavnom traktu. Poremećaj može nastati zbog smanjenja povoljnih mikroorganizama, prerastanja potencijalno štetnih mikroogranizama ili zbog smanjenja cjelokupne mikrobiološke raznovrsnosti. Poremećaji crijevne mikrobiote su povezani s brojnim stanjima i sindromima, uključujući upalne bolesti crijeva, kolorektalni karcinom, sindrom iritabilnog kolona, alergijske bolesti, pretilost, metabolički sindrom, celijakija. Danas se sve više proučava odnos prehrane i mikrobiote te učinak prehrambenih intervencija. U kliničkoj praksi je sve prisutnija upotreba nutritivne sastavnice poput probiotika, prebiotika i simbiotika. Probiotici su živi mikroorganizmi s pozitivnim utjecajem na ravnotežu u crijevu, dok su prebiotici nerazgradive sastavnice hrane bazirane na selektivnoj stimulaciji povoljnih crijevnih bakterija. I probioticima i prebioticima se pripisuju brojna pozitivna djelovanja na čovjekovo zdravlje. TakoĎer pronalaze se drugi načini manipulacije crijevnom mikrobiotom u želji za prevencijom ili potencijalnom tretiranju bolesti povezanih s poremećajima mikrobiote (poput fekalne transplantacije mikrobiote).The human gut microbiota harbours over 100 trillion microorganisms that form the intestinal microbiota which is 10 times more than the number of all human cells in the organism. The development of the ecosystem of the intestinal microbiota begins with birth and established intestinal microflora during life is relatively stable, but susceptible to the influences of exogenous and endogenous factors (diet, use of medications, disease, ageing). The composition of the intestinal microbiota is unique for each person and it is difficult to define what the healthy microbiota is. The intestinal microbiota plays an important role in human health and disease. The importance of intestinal microbiota is manifested through their impacts on human physiology, metabolism, diet and immune function. Dysbiosis or disorder of intestinal microflora is a term describing the disruption of the natural balance of microorganisms in the digestive tract. The disorder may occur due to loss of beneficial micorbial organisms, expansion of pathobionts or potentially harmful microorganisms and loss of overall micorbial diversity. Disorders of gut microbiota are associated with a variety of conditions and syndromes, as well as diseases including inflammatory bowel disease, colorectal cancer, irritable bowel syndrome, allergic diseases, obesity, metabolic syndrome, celiac disease. Today, there is great interest in observing the relationship between diet and microbiota and impact of food interventions. In clinical practice is an increased use of nutritional components such as probiotics, prebiotics and synbiotics with the aim to restore balance in the compostion of microbiota. Probiotics are live microorganisms with a positive impact on the balance in the intestine, while prebiotics are degradable components of foods based on selective stimulation of favourable intestinal bacteria. To the probiotics and prebiotics are attributed a number of positive effects on human health. Also, other ways are today investigetd and applied such as intestinal manipulation with microbiome to restore the desired potential of our “bacterial alliance” for the prevention and/or treatment of diseases associated with disorders of the microbiota (such it is a faecal microbiota transplantation mesure)