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Nutrition is one of the most important aspects of pig farming. Each category of pigs is fed by a special compound feed for a given group of animals. New alternatives to these drugs are still being explored due to the 2006 ban on growth-promoting antibiotics. Probiotics, prebiotics and phytobiotics, which have a positive effect on the digestive system of all categories of pigs, are becoming very popular substitutes.

Aging is associated with natural biological changes, which result in a decrease in the functional capacity of the body, which is also accompanied by an increased incidence of inflammatory processes that contribute to the development of neurodegeneration. The intestinal microbiota and its interaction with the intestine and the central nervous system play a key role in maintaining the function of biological homeostatic systems at an older age. This opens the possibility of influencing or modifying human microbiota for the development of therapeutic strategies. Based on the analysis of stool samples by HPLC MS / MS, the study confirmed the effect of selected probiotics on the modification of metabolic pathways and the proper functioning of the microbiota per se. The greatest effects were observed on tyrosine metabolism, tryptophan metabolism, arachidonic acid metabolism and bile acid biosynthesis metabolism. A positive effect of selected probiotic bacteria was found in the memory component of cognitive functions. Significant improvements were observed in verbal learning and verbal memory. In subjects with mild cognitive impairment, the progression of cognitive deficit has been slowed. Significant improvement was also observed for executive functions. These findings were not followed by a subjective...

Hintergrund: Daidzein ist ein Phytohormon, das vor allem über pflanzliche Ernährung wie Soja aufgenommen und von Darmbakterien zu Equol umgewandelt wird. Nur etwa ein Drittel der westlichen Bevölkerung kann – bei entsprechender Mikrobiom-Flora - Daidzein in Equol umwandeln. Bei Frauen mit Polyzystischem Ovarsyndrom (PCOS) könnte dieser Anteil noch geringer ausgeprägt sein. Außerdem scheint es einen Zusammenhang zwischen PCOS und dem Darmmikrobiom zu geben, das bei Frauen mit PCOS auch eine verringerte Biodiversität aufweist. Da es bereits Daten zu gesundheitlichen Vorteilen von Equol bei PCOS gibt, könnte besonders diese Gruppe von der Equol-Produktion profitieren. Ziel dieser Studie war es, den Anteil an Equol-Produzentinnen bei Frauen mit PCOS zu erheben und zu prüfen, ob Probiotika Einfluss auf den Equol-Produktionsstatus haben. Methodik: 30 Probandinnen mit diagnostiziertem PCOS, die randomisiert in 3 Gruppen zu je 10 Personen eingeteilt wurden, konsumierten über 3 Monate eines von drei Probiotika. Vor und nach Intervention wurden hormonelle, klinische und metabolische Parameter, die in Zusammenhang mit PCOS stehen, gemessen, sowie der Equol-Produktionsstatus bestimmt. Für letzteres wurden die Konzentrationen von Equol und Daidzein im Harn mittels GC-MS gemessen und deren Verhältnis zur Basis 10 logarithmiert. Als Cut-off für die Equol-Produktion wurde der log10-Grenzwert mit -1,75 festgelegt. Ergebnisse: Der Anteil der Equol-Produzentinnen in dieser PCOS-Kohorte lag zum Zeitpunkt des Studienbeginns bei 15 %. Bei drei Probandinnen änderte sich während des Studienzeitraumes der Equol-Produktionsstatus. Schlussfolgerung: Der Anteil an Equol-Produzentinnen ist bei Frauen mit PCOS geringer als in der nicht betroffenen Bevölkerung. Eine Änderung des Darm-Mikrobioms und die Fähigkeit, Equol aus Daidzein zu produzieren, kann bei einigen Patientinnen innerhalb von drei Monaten erreicht werden. Background: Daidzein is a phytohormone that is mainly absorbed from plants e.g. soy and converted to equol by intestinal bacteria. Only about a third of the western population can convert daidzein into equol, based on a specific gut microbiome. This proportion appears to be even lower in women with polycystic ovary syndrome (PCOS). In addition, a connection between PCOS and the gut microbiome has been described, showing a reduced biodiversity in women with PCOS. Since data are already available on the health benefits of equol in PCOS, this group in particular could benefit from equol production. The aim of this study was to determine the proportion of women producing equol in women with PCOS and to examine whether probiotics have an influence on the status of equol production. Methods: 30 participants with diagnosed PCOS, who were randomly divided into three groups of ten people each, consumed one of three probiotics for three months. Before and after the intervention, hormonal, clinical and metabolic parameters associated with PCOS were measured and the equol production status was determined. For the latter, the concentrations of equol and daidzein in the urine were measured using GC-MS and their ratio to base 10 was logarithmized. The log10 value -1.75 was set as the cut-off for equol production. Results: The samples from 25 test subjects could be analyzed and included in the evaluation. The proportion of female equol producers in this PCOS cohort was 15% at the start of the study. In three test subjects, the equol production status changed during the study period. Conclusion: The proportion of women producing equol is lower in women with PCOS than in the healthy population. The ability to produce equol from daidzein via microbiome changes might be achieved within three months. Abweichender Titel laut Übersetzung der Verfasserin/des Verfassers Masterarbeit FH JOANNEUM 2022

En urinvägsinfektion (UVI) är ett samlingsnamn för infektioner som förekommer i urinvägarna och som drabbar cirka 2% av Sveriges befolkning under deras första levnadsår. Urinvägsinfektionen orsakas främst av tarmbakterier och den mest förekommande patogenen är den gramnegativa Escherichia coli. Då en infektion kan uppstå på flera ställen i urinvägarna så har den olika namn. En infektion i blåsan kallas för cystit och en infektion som spridit sig till de övre urinvägarna och njurarna kallas för pyleonefrit. En anledning till att infektionen fortskrider till pyelonefrit kan vara på grund av vesikoureteral reflux (VUR). Detta innebär att urin flödar tillbaka från urinblåsan och upp genom urinledaren mot njurarna. Detta ökar även risken för recidiverande UVI. I många fall kräver detta minst tre antibiotikabehandlingar per år, vilket i sin tur ökar risken för en utvecklad antibiotikaresistens. Forskare försöker därför komma på alternativ som kan hjälpa till att förebygga nya infektioner. Ett exempel på ett sådant alternativ är probiotika. Det är levande organismer som i rätt mängd kan vara fördelaktiga för personens hälsa. Syftet med denna litteraturstudie är därför att undersöka om antibiotika och probiotika som profylax kan minska risken för en återkommande UVI. Därmed kunde även eventuella nackdelar med de två behandlingssätten studeras. För att kunna göra detta granskades sex stycken studier som undersökte effekten av antibiotika och/eller probiotika i samband med återkommande UVI hos barn. Slutsatsen är att det inte det inte finns någon signifikant skillnad i effekten mellan trimetoprim-sulfametoxazol och andra generationens cefalosporiner eller Lactobacillus acidophilus. Däremot kan ett ökat antal stammar av probiotika i jämförelse med placebo vara fördelaktigt i syfte att förebygga en återkommande UVI. A urinary tract infection (UTI) is a collective name for an infection that occurs in the urinary tract and it affects about 2% of Sweden's population during their first year of life. The urinary tract infection is caused mainly by intestinal bacteria and the most common pathogen is the gram-negative E. coli. The infection can occur in different parts of the urinary tract, and it is therefore called by different names. An infection of the bladder is called cystitis and an infection that has spread to the upper urinary tract and kidneys is called pyelonephritis. One of the reasons leading to progression of an infection to pyelonephritis is vesicoureteral reflux (VUR). VUR implies that urine flows back from the bladder and up through the ureter, towards the kidneys. This also increases the risk of recurrent UTI. In many cases, this requires at least three antibiotic treatments per year, which in turn increases the risk of developing antibiotic resistance. Researchers are therefore trying to come up with alternatives that can help prevent new infections. An example of such an alternative is probiotics, which are a live bacteria. The most common probiotics are bacteria that belong to the genera called Lactobacillus and Bifidobacterium. Different types of probiotics may have different effects and they can be beneficial to a person´s health when ingested in the right amount. The purpose of this literature study is therefore to investigate whether antibiotics, in comparison with probiotics can reduce the risk of a recurrent UTI, and thereby examine the possible disadvantages of the two treatment methods. To be able to do this, six studies were examined that studied the effect of antibiotics and/or probiotics in connection with recurrent UTI in children. It is concluded that there is no significant difference in the effect between trimethoprim-sulfamethoxazole and second-generation cephalosporins or Lactobacillus acidophilus. However, an increased number of strains of probiotics may be beneficial compared to placebo in order to prevent a recurrent UTI.

Thesis contains informations about right stabling and nutrition of calfs. It´s include importance of probiotic supplements and their influence to growth and health of cows. Newborns weight in seven days after birth was similar (54 kg) in every of three groups. Significant diferences were registered at the end of these monitoring, in ninety days after birth. First Group witch consumed RumiForm Digest had average wight 126 kg. Groups witch consumed RumiForm Digest with bacteria mixture, had average weight 146 kg. In every monitored groups diarrheal was detected. The biggest frequency was detected at group, witch consumed RumiForm Digest with bacteria mixture. There was detected 9% diarrheal diseases in total 48 calfs. Deads were detected only in the group of calfs whitche eat RumiForm Digest with probiotics during the experiment. Total mortality was less thas 2%. There wasn´t shown influence of probiotics to calfs growth (p-value (calves weight on the 7th day after birth) = 0,63; p-value (calves weight on the 90th day after birth) = 0,31, p-value greater than 0,5), either to calfs health (p-value (comparison of diarrhea rates) = 0,67; p-value (death) = 0,82, p-value greater than 0,5). Can not be said, that the eating of probiotics supplements had pozitive influence to calfs grow and health.

Probiotics are living microorganisms which show positive effects on human health if consumed in a sufficient quantity. Probiotics have been under a lot of research recently, however their effectiveness in terms of treatment or prevention of diseases has not been supported by a sufficient number of studies and research yet. The thesis summarizes the existing knowledge about probiotics, characterizes individual types of probiotic organisms, describes possible sources of probiotics and their impact on human health. Theoretical part of the thesis deals with the definition of the concept of probiotics, also describes prebiotics and synbiotics which are closely related to this topic. characteristics of individual groups of probiotics as well as their impact on human health and possible use in the treatment of diseases as a form of biological treatment are also included. Furthermore the sources of probiotics both in the form of foods containing probiotics and in the form of probiotic dietary supplements are described. At the end of the theoretical part, recommendations for receiving and selecting a suitable source of probiotics are summarized. The aim of the practical part was to find out if the general public is aware of probiotics. Questions about preferences in the selection and consumption of...

The target of the research was to analyze the effect of antidiarrheal feed additives on calves average daily weight gain. In the study, 120 calves were analyzed. Newborns were selected into 3 treatment groups, control (without supplementation) and group with Ascophyllum nodosum (prebiotics), and mixture of Lactobacillus sporogenes, Enterococcus faecalis and Bifidobacterium bifidum (probiotics). Individual body weight of animal were determined after 2 hours postpartum. Monitoring of the growth intensity, as well as health status were done till 56 days of age. Significant effects (P, Cílem této studie bylo prokázání vlivu krmných aditiv s protiprůjmovým účinkem na hmotnostní přírůstky a zdraví telat. Do experimentu bylo zařazeno celkem 120 telat. Po narození byla telata rozdělena do tří skupin: Ascophyllum nodosum (hydrolyzát hnědých mořských řas, prebiotikum), kombinaci Lactobacillus sporogenes, Enterococcus faecalis a Bifidobacterium bifidum (probiotikum) a kontrolní skupinu. Všechna telata byla zvážena do dvou hodin po narození. Přírůstky a zdravotní stav byly sledovány od narození do 56. dne věku. Ve srovnání s kontrolní skupinou byl nalezen signifikantní vliv aplikovaných krmných aditiv u probiotické skupiny u hmotnostních přírůstků 21. den po otelení (P

Bakgrund: Irritable bowel syndrome (IBS) karakteriseras av obehag i magtarmkanalen och förändrade avföringsvanor. Sjukdomen delas in i subtyperna IBS-C (förstoppning), IBS-D (diarré), IBS-M (blandad) och IBS-U (odiagnostiserad). Patofysiologin och etiologin är inte klarlagd, men bland annat störd tarmflora och inflammation har föreslagits. Prevalensen är 10-20 %. Denna litteraturstudie fokuserar på probiotika som behandling vid IBS-D, ett område med ökat intresse inom forskningen. Syfte och Metod: Syftet med litteraturstudien är att undersöka effekten och säkerheten av probiotika Clostridium butyricum, Saccharomyces boulardii, Bio-Kult® samt BIO-25 på IBS-D patienter. Sökning i den medicinska databasen PubMed januari 2021 genererade 5 dubbelblindade, randomiserade, placebokontrollerade studier. Resultat: Bio-Kult® och Clostridium butyricum resulterade i signifikant skillnad på symtom jämfört med placebo. Den förstnämnda hade inga biverkningar, medan den senare medförde åtta biverkningsfall. Saccharomyces boulardii förbättrade interleukin-8 (IL-8), tumor necrosis-α (TNF-α), IL-10 och IL-10/IL-12 kvoten, men inte symtomen jämfört med placebo. Nära hälften av deltagarna fick lättare biverkningar. BIO-25 medförde en förbättrad tarmflora vad gäller Lactococcus och Lactobacillus, men det gav inga symtomförbättringar jämfört med placebo. Inga biverkningar upptäcktes. Quality of Life (QOL) förbättrades i alla studier där variabeln mättes. Slutsats: Liksom tidigare studier av andra forskare genererade artiklarna i detta arbete ett tvetydigt utfall. En anledning till det varierande resultatet kan härledas till placeboeffekten. En del av resultaten är hoppingivande, speciellt när det gäller QOL. Samtidigt antyder undersökningarna att probiotikans effekt är beroende av tarmflorans sammansättning. Saccharomyces boulardii förbättrade IL-8, TNF-α, IL-10 och IL-10/IL-12 kvoten, medan BIO-25 förbättrade Lactococcus och Lactobacillus. Fyra av fem studier hade en bra biverkningsprofil. Slutsatsen blir att probiotika har viss effekt på IBS-D patienter och få biverkningar. Fler och större studier behövs för att få en klarare bild av probiotikans effekt och biverkningar på IBS-D patienter. Background: Irritable bowel syndrome (IBS) is characterized by discomfort in gastrointestinal tract and change in the bowel motility. The subtypes of the disease are diveded into IBS-C (constipation), IBS-D (diarrhea), IBS-M (mixed) and IBS-U (undefined). The pathophysiology and etiology are incompletely understood but changed gut microbiota and inflammation has been proposed among other things as the underlying causes. The prevalence is 10-20 %. This study focused on probiotics as a treatment for IBS-D, which has been used during the last decade in the treatment of the disease. Purpose and method: This study aimed to assess the efficacy and safety of Clostridium butyricum, Saccharomyces boulardii, Bio-Kult® and BIO-25 on IBS-D patients. Searches in the medical database PubMed in January 2021 resulted in 5 double-blind, randomized, placebo-controlled trials. Results: Bio-Kult® and Clostridium butyricum resulted in significant differences compared with placebo. The prior had no adverse events, while the latter had eight adverse events. Saccharomyces boulardii improved interleukin-8 (IL-8), tumor necrosis-α (TNF-α), IL-10 och IL-10/IL-12 ratio, but not the symptoms compared with placebo. Nearly fifty percent of the patients had mild adverse events. BIO-25 resulted in improved Lactococcus and Lactobacillus but showed no improvements in symptoms compared with placebo. No adverse events were discovered. Quality of Life (QOL) improved in all studies the variable was measured. Conclusion: The outcome of this study was inconclusive and thus similar to previous studies. One of the reasons for the various outcomes can be derived from the placebo effect. In some of the results the use of probiotic treatment were positive, especially when it comes to the improvement of QOL. The studies suggested that the effect of probiotics is dependent on the composition of the gut microbiota. Saccharomyces boulardii improved IL-8, TNF-α, IL-10 och IL-10/IL-12 kvoten, while BIO-25 improved Lactococcus och Lactobacillus. Four out of five studies had a good outcome when it comes to adverse events. The conclusion of this thesis is that probiotics have some effect on IBS-D patients and few adverse events. Larger studies need to be done to evaluate the effect of probiotics and its adverse events.

Die Modulation der peripheren T-Zell-Immunantwort, induziert durch Veränderungen in der Besiedelung des Darmmikrobioms, wird mit der Entwicklung von neurologischen Erkrankungen assoziiert. Bifidobacterium breve ist ein typischer Besiedler des Darmmikrobioms und wird vor allem als Probiotikum verwendet. Rezente Studien vermuten, dass der Einsatz von Probiotika das Ergebnis von neuroinflammatorischen Erkrankungen wahrscheinlich verbessern könnte, indem sie die Zytokin- und Neuromodulatorproduktion von peripheren Immunzellen beeinflussen. Daher ist es von Interesse den immunmodulatorischen Einfluss des probiotischen Bakterienstamms B. breve auf die periphere T-Zell-Antwort im Kontext der Mikrobiom-Darm-Hirn-Achse genauer zu identifizieren. Dafür wurden mononukleäre Zellen des peripheren Blutes (PBMCs) aus peripherem Vollblut gesunder erwachsener Probanden isoliert und mit hitzeabgetöteten B. breve und weiters mit Phytohämagglutinin-L (PHA-L) oder einem CD3/CD28-Agonisten stimuliert, um T-Zellen zu aktivieren. Die Konzentrationen von IFN-γ, TNF-α, IL-17, IL-10 und von BDNF wurden in den Zellkulturüberständen von PHA-L oder CD3/CD28-aktivierten PBMCs mittels Enzyme-Linked Immunosorbent Assay (ELISA) gemessen. Die Ergebnisse zeigten, dass B. breve die Produktion des anti-inflammatorischen Zytokins IL-10 beeinflusst, da CD3/CD28-aktivierte PBMCs die mit B. breve stimuliert wurden signifikant geringere Mengen von IL-10 produzierten. Zudem zeigte sich ein Trend, dass die Sekretion von TNF-α und IL-17 von CD3/CD28-aktivierten PBMCs nach Stimulation mit B. breve herunterreguliert wurde. Allerdings hatte B. breve keinen signifikanten Effekt auf die BDNF Sekretion von stimulierten PBMCs. Zusammenfassend konnten wir zeigen, dass der probiotische Bakterienstamm B. breve einen immunmodulatorischen Einfluss auf periphere Immunzellen hat, indem es die Produktion von IL-10 verminderte, das hauptsächlich von regulatorischen T-Zellen sezerniert wird. Zusätzlich unterdrückte B. breve tendenziell die Zytokinantwort von Th1- und Th17-Zellen, was während einer laufenden Entzündung von Vorteil sein könnte. Dennoch sind weitere Studien, insbesondere auf Ebene einzelner Zellen erforderlich, um den immunomodulatorischen Effekt von B. breve auf die T-Zell-Immunität zu entschlüsseln. Modulations of the peripheral T cell response induced by changes of the gut microbial colonization have been shown to be involved in the development of neuroinflammatory diseases. Bifidobacterium breve represents one of the predominant bacterial species in the human gut microbiome and is used as a probiotic. Recent studies suggest that the use of probiotics might improve the outcome of neuroinflammatory diseases by influencing cytokine and neuromodulator production of peripheral immune cells. Therefore, it is of interest to investigate the immunomodulatory impact of the probiotic bacterial strain B. breve on the peripheral T cell response in the context of the microbiome-gut-brain axis. Peripheral blood mononuclear cells (PBMCs) were isolated from whole peripheral blood from healthy adult volunteers and stimulated with heat-killed B. breve as well as phytohaemagglutinin-L (PHA-L) or a CD3/CD28 agonist in order to activate T cells. The levels of IFN-γ, TNF-α, IL-17, IL-10 and BDNF were measured in the cell culture supernatants of PHA-L or CD3/CD28-activated PBMCs by enzyme-linked immunosorbent assay (ELISA). B. breve influences the cytokine release of IL-10, as CD3/CD28-activated PBMCs produced significantly lower levels of IL-10 in response to stimulation with B. breve. Additionally, a tendency of B. breve to decrease the production of the pro-inflammatory cytokines TNF-α and IL-17 was observed. However, B. breve had no significant effect on BDNF production by PBMCs. In conclusion, we demonstrated that the probiotic bacterial strain B. breve has an immunomodulatory impact on peripheral immune cells by decreasing the regulatory T cell-associated cytokine IL-10. Additionally, B. breve tended to suppress the Th1 and Th17 cytokine response which might be beneficial during ongoing inflammation. Nevertheless, further studies, especially on the single cell levels, are needed to decipher the immunomodulatory effects of B. breve on T cell immunity.

The intestinal microbiome is formed by trillions of microorganisms that accompany us throughout our lives. Commensal gut microorganisms, as a complex system, interfere with diet processing and subsequent spectrum of released metabolites, which are involved in communication with other systems of the human body. Recently, a link between intestinal microbiota dysbiosis and activation of the immune response has begun to emerge. This pathophysiological condition is associated with the loosening of the tight junctions of the gut epithelial barrier, which could together with prolonged immune inflammation lead to what is known as irritable bowel syndrome. This disease is not only related to symptoms associated with bowel discomfort, but also to effects on afferent nerve endings. This connection has been called as the gut-brain axis and became the link between the gut microbiota and psychiatric diseases. This work is summing up the actual knowledge on this topic and offers a comprehensive overview of the subject from both an immunological and a microbiological point of view. Key words: gut-brain axis, depression, anxiety, antibiotics, antidepressants, probiotics, IBS

Mjölksyrabakterier är mikroorganismer som bildar mjölksyra när de bryter ned socker. Dessa bakterier förekommer naturligt i människans kropp och tillhör tarmens normalflora. De hjälper dessutom till med att skydda människan från patogena mikroorganismer. Maten som intas idag innehåller mycket lite av mjölksyrabakterier och bör därför berikas på annat sätt. BioGaia som är ett svenskt bioteknikföretag, har forskat på mjölksyrabakterien Limosilactobacillus reuteri och substansen reuterin. BioGaias produkter innehåller mjölksyrabakterien Limosilactobacillus reuteri som bidrar till en balanserad tarmflora. Stabilitetsstudier är en viktig aspekt när en ny produkt utvecklas där produktens hållbarhet behöver undersökas under olika förhållanden. Haltbestämningen som är en del av stabilitetsstudien, görs idag på bakterier i de olika produkterna på BioGaia med plattmetoden, d.v.s. bakterieodlingar. Processen för plattmetoden tar cirka tre dagar tills att ett resultat kan fås. Syftet med studien var att jämföra plattmetoden med flödescytometri på probiotiska prover, för att se om resultatet av haltbestämningen av antalet levande bakterier blir samma med de olika metoderna och om det är möjligt att ersätta plattmetoden med flödescytometri för probiotiska prover. Studien har visat att skillnaden mellan resultatet från plattmetoden och flödescytometrin på probiotiska prover, är större än förväntat. Storleken på skillnaden varierar mellan prover. Resultatet har dock inte ett tydligt mönster som gör det möjligt att avgöra ifall det är möjligt att ersätta plattmetoden med flödescytometri.

Innate lymphoid cells type 3 (ILC3) are a group of relatively newly discovered lymphocytes that lack an antigen-specific receptor. Nevertheless, their important role of immune regulators on mucous membranes is evident. In addition to the development of lymphoid tissue in embryogenesis, and during ontogenesis, postnatally, ILC3 are mainly involved in maintaining intestinal homeostasis and controlling intestinal microbiota. ILC3 produces various cytokines that stimulate surrounding intestinal cells to produce antimicrobial peptides and maintain epithelial wall integrity. The major cytokine produced by ILC3 is IL-22. Th17 lymphocytes and ILC3 are similar in many respects but differ significantly in some functions. ILC3 can regulate adaptive immunity cells towards an antimicrobial response without inducing inflammation. They are also directly connected to cells of the nervous system. Some probiotic bacterial strains produce metabolites that directly affect ILC3. This mechanism could be used in new therapeutic approaches to ameliorate the severity of diseases where changes in microbiota composition and function are inducing proinflammatory responses of the host. Key words: innate lymphoid cells; IL-22; antimicrobial peptides; probiotics; microbiota

The presence of bacteria in the human body is a crucial factor for immune system development and its appropriate functioning. This bachelor thesis focuses on the beneficial effects of Bacteroides fragilis and explores the possibility of altering its abundance in the colon by dietary intervention. Both Czech and foreign literature was reviewed and the practical part was carried out using a questionnaire survey. The research indicates that it is possible to affect the proportional representation of Bacteroides fragilis in the colon with specific nutrients and dietary habits. Additionally, the theoretical part describes the benefits of this bacterial species on the human immune system. Bacteroides fragilis produces short-chain fatty acids, antimicrobial substances and polysaccharide A, which are the principal components that influence the host. The practical part builds upon the findings of the theoretical part. It investigates the knowledge of a random sample of Czech citizens about the effect of diet on microbiota composition. It also explores people's view on probiotics and their acquaintance with food composition. The conclusion of the thesis is a correlation between the theoretical and practical part. The intestinal microbiota is a relatively compact unit with complex interactions. Diet can not...

Introduction: Physiological microflora is characterised by wide diversity. The microbial community is mostly composed of bacteria, but also includes fungi, archaea and viruses. Anaerobic commensal bacteria (Firmicutes and Bacteroidetes) dominate 90% of the colon. The composition and products of the gut microbiota have a significant effect on an individual's immune system, and their interactions may ultimately promote immune tolerance or inflammatory immune response. Blood cell transplantation (HSCT) and its associated standard procedures of conditioning, antibiotic exposure and dietary prophylaxis represent modification and disruption of the gut microbiota leading to the development of some serious post-transplant complications affecting the OS (overall survival) and TRM (treatment related mortality) of patients. Objectives: The aim of this work was to investigate the representation of individual bacterial strains in patients undergoing allogeneic HSCT, as well as the effect of transplantation on the composition and diversity of their gut microbiota. Methods: Stool samples were obtained from 52 patients who underwent an allogeneic hematopoietic cell transplant at the Institute of Hematology and Blood Transfusion in Prague. A cut-off date for the first sample was set for the start of...

Title: Probiotic prophylaxis in the prevention of necrotizing enterocolitis in preterm infants Background: Necrotizing enterocolitis (NEC) is one of the most serious gastrointestinal emergencies and a leading cause of death amongst premature infants. Early detection is difficult, prevention is essential. Probiotics have been proposed as a measure to prevent NEC and prophylactic use has been routine in Norwegian neonatal intensive care units (NICUs) since 2014. However, recent publications have raised questions regarding the efficacy and safety of probiotics, especially in extremely premature infants (ELBW). Updated reviews and guidelines express concerns and the newest edition of UpToDate now advises against routine prophylactic use. Objective: The thesis’ objective is to address the following questions: Does prophylactic administration of probiotics reduce the incidence of NEC in premature born infants, including ELBW infants1? And does the evidence for efficacy and safety support routine administration in NICUs? Material and methods: A systematic literature search was performed in PubMed. Additional literature was identified through Norwegian NICUs’ method books, UpToDate and articles provided by my project thesis supervisor. Results: Of 21 included studies, 18 (86%) found a significant reduction in incidence of NEC in premature infants. Of these 18 studies, 12 had pooled data across the entire premature population. Seven out of 21 studies separated the ELBW infants, only one (14%) of which found a significant reduction in NEC in this subgroup. Five additional studies reported insufficient data on ELBW infants. Two studies performed separate analysis of efficacy adjusted for study location; one found the reduction in NEC to be greatest in Asian populations and the other found significant reductions only in Asian countries and Australia. Nine of the 18 studies that found a significant reduction in NEC recommended routine implementation of probiotics as a preventive measure. Conclusion: Probiotics seem to be efficacious in the prevention of NEC in premature infants, but only in VLBW and higher weight groups. Conversely, the evidence is very limited for ELBW infants, and studies suggest there might not be an effect at all in this weight group. Product safety remains a concern as long as probiotics classify as dietary supplements and thereby avoid the stringent quality controls of pharmaceuticals. Scandinavian based studies are needed to apply the current knowledge onto Scandinavian children, and a change in current practice in Norwegian NICUs could be warranted.

Der enteropathogene Escherichia coli (EPEC) ist weltweit als Erreger der Säuglingsdiarrhoe bekannt. In der Therapie akuter Gastroenteritiden im Kleinkind- und Säuglingsalter erfolgt immer häufiger die Gabe von Probiotika. Im Rahmen dieser Arbeit wurde der Effekt des probiotischen Lactobacillus rhamnosus W65 auf die Virulenz des Pathogens und dessen Adhärenz am gastrointestinalen Epithel anhand verschiedener Inkubations- und Infektionsszenarien untersucht. Die Ergebnisse der vorliegenden Arbeit zeigen einen reduktiven Effekt des Lactobacillus rhamnosus W65 auf die Transkription ausgewählter Virulenzgene (bfpA, espD, eae) des EPEC E2348/69. Darüber hinaus wurde das Wachstumsverhalten des EPEC E2348/69 in unterschiedlichen Nährmedien studiert. Das Wachstum des Pathogens in einer Mischung aus LB- und MRS-Medium führte zu Veränderungen der Transkriptionsraten ausgewählter Virulenzgene, der Proteinexpressionsmuster und des Erscheinungsbildes in der Elektronenmikroskopie.

Infektionskrankheiten sind weltweit eine Haupttodesursache. Die Zunahme der Antibiotikaresistenz macht den dringenden Bedarf an neuen therapeutischer Strategien (z.B. vorbeugende Probiotika) deutlich. E. coli Nissle 1917 (EcN) verfügt über zahlreiche Fitnessfaktoren, die für die probiotische Natur von EcN wesentlich sind. Kolon- Zelllinien und das Bioreaktor Rotating Wall Vessel (RWV) System wurden zur Analyse eingesetzt. Des bietet dynamische Kulturbedingungen um die zelluläre Antwort von Wirts-Zellen auf Bakterien zu untersuchen. Der probiotische EcN stellte die epitheliale Barrierefunktion nach einer Schädigung durch EPEC wieder her. Die vorliegende Studie trägt zum Verständnis der Mechanismen bei, die die Wechselwirkungen zwischen Wirt und Probiotika steuern. Die Verwendung von Zellkulturmodellen, die das Darmepithel besser nachbilden, eröffnen den Weg für die Entwicklung neuer, besserer Strategien zur Kontrolle der Immunantworten des Wirtes durch Probiotika.