No description available.

Background: Mild Cognitive Impairment (MCI) is seen as a state between normal aging and dementia, with patients having an increased risk of developing Alzheimer’s disease (AD) and other sorts of dementia. MCI has been linked to a change in gut microbiota which impacts the microbiota-gut-brain axis (MGBA), consequently affecting neurological functions. A way of altering microbiota and thereby promoting cognitive health is through the administration of prebiotics, probiotics, and synbiotics. Aim: This systematic literature review aims to assess the impact of prebiotics, probiotics, and synbiotics on MCI by compiling existing data on the matter. Methods: Three databases - Web of Science, Cochrane, and PubMed - were searched and articles were included based on the following inclusion criteria: (1) randomized clinical trials (RCTs), (2) conducted on adults evaluated with MCI during the study, (3) including a prebiotic, probiotic, or synbiotic intervention of any kind, (4) comparing the intervention with a placebo or control group, (5) written in English, (6) reporting the main outcome of cognitive function using any neuropsychological evaluation test. Results: Five studies were included in the final selection. These studies showed that cognitive function improved after probiotic intervention, significantly affecting several cognitive domains: attention, calculation, orientation in time, and delayed memory. Two studies showed that subjects with low cognitive scores at baseline benefited more from probiotic supplementation compared to high-scoring subjects. Conclusions: Probiotics appear to improve cognition in MCI subjects; however, further research is needed to conclude the effects of prebiotics and synbiotics.

In 1867, Dr. Wilhelm Busch decisively exposed a cancer patient to erysipelas and notedtumor regression. The practice of inoculating tumors with bacteria became more widespread with the work of Dr. William Coley, beginning in 1891, who inoculated inoperable tumors and observed complete regressions though at times notable toxicity. These microbial manipulations of immunity now form the roots of cancer immunotherapy in modern history. Alongside the blossoming of cancer immunology since, the development of techniques to alter biological systems has given rise to synthetic biology. Together, these fields allow the programming of biological systems to precisely guide the cancer-immune interplay. As mammalian immunity targets bacterially-derived antigens due to the immunostimulatory nature of microbes, and tumors express various antigens, synthetic alteration of microbes to function as safe and effective anti-tumor vaccines is a natural proposition. In this work, I describe my development of such a microbial system comprised of a synthetic tumor-antigen construct optimized for expression in bacteria, the immunotoxin Listerolysin O, and a genetically edited probiotic E. coli chassis with multi-functional protease deletions. This platform encodes and delivers high levels of diverse tumor antigens sets, remodels the tumor microenvironment, and stimulates productive and durable anti-tumor immunity to control and eliminate primary and metastatic tumors. We show that this system induces tumor antigen-specific CD4+ and CD8+ T cells, activates NK cells, recruits and activates dendritic cells, and reduces immunosuppressive regulatory T cells, B cells, and myeloid cells within the tumor microenvironment. This work thus establishes a new class of anti-tumor vaccine which modulates all arms of immunity to achieve robust anti-tumor efficacy.

We investigated the hypothesis that exposure to inhaled diesel exhaust PM can alter the gut microbiome and intestinal integrity, thereby promoting systemic inflammatory response and early CVD risk, which are exacerbated by HF diet. Furthermore, we investigated whether the observed exposure and diet-mediated outcomes could be mitigated through probiotic treatment. We performed an exposure study on C57Bl/6 male mice, placed on either a low fat (LF) diet or a high-fat (HF) diet, and exposed via oropharyngeal aspiration to 35 μg diesel exhaust particles (DEP) suspended in 35 μl of sterile saline or sterile saline controls (CON) twice a week for four weeks. A subset of mice on HF diet were dosed with 0.3 g/day (PRO, ~7.5x108 CFU/day) of probiotic Ecologic® Barrier 849 (Winclove Probiotics) in drinking water during the course of the study. For our first aim, we investigated the alterations in the gut microbiome, measured circulating cytokines and lipopolysaccharide (LPS), and measured CVD biomarkers in the heart. Our results revealed that exposure to inhaled DEP results in gut dysbiosis characterized by expansion of the phyla Verrucomicrobia and Proteobacteria and reduction in Actinobacteria, which was exacerbated by HF diet. Probiotics mitigated the DEP-mediated expansion of Proteobacteria and re-established Actinobacteria in the intestine of HF animals. Furthermore, we determined that exposure to inhaled DEP increases systemic LPS and inflammatory markers IL-1α, IL-3, G-CSF, and TNF-α. Furthermore, we found that inhaled DEP exposure results in increased CVD biomarkers sICAM-1, sP-selectin, and thrombomodulin in the heart. Probiotic treatment was effective in attenuating LPS, inflammatory responses, and CVD biomarkers in HF animals, validating the involvement of the microbiome in mediating inhaled DEP-mediated responses. Considering the effects we observed in the microbiota and systemically of the HF and probiotic treatment animals, we investigated the effects of inhaled DEP on intestinal integrity and inflammation in HF ± PRO animals. Our results showed that inhaled DEP in conjunction with HF diet promotes increased goblet cell and mucin 2 expression, tight junction (TJ) proteins (claudin-3, occludin, and zonula occludens (ZO)-1) expression, matrix metalloproteinase (MMP)-9, toll-like receptor (TLR)-4, and decreased TNF-α and IL-10. Moreover, we found that probiotics promoted intestinal immune response following inhaled DEP exposure characterized by an increase in TNF-α and IL-10 and showed variable expression of TJs in the intestine. In conclusion, we found that inhaled DEP exposure results in changes in gut microbial profiles, altered intestinal integrity, systemic inflammation, and increased CVD biomarkers, which are exacerbated by HF diet. The use of probiotics in this study proved to be pivotal in understanding the microbiome's influences on the regulation of intestinal integrity, intestinal inflammation, systemic inflammation, and cardiovascular system following inhaled DEP exposure with HF diet.

Salmonella est une bactérie zoonotique habituellement associée à un état de portage asymptomatique chez le porc. L’humain peut s’infecter principalement avec la consommation de produits dérivés du porc contaminés ce qui peut causer des gastro-entérites. Parfois, des complications peuvent avoir de graves conséquences. Quelques méthodes sont présentement utilisées pour contrôler Salmonella à la ferme, mais leur efficacité est variable. Les probiotiques ont été documentés comme une alternative intéressante aux antimicrobiens, notamment les Bacillus spp. Certaines études rapportent l‘efficacité des Bacillus contre Salmonella en plus d’avoir la capacité d’améliorer la santé digestive des porcs en partie grâce à leur grande production d’enzymes. Ce projet vise à caractériser l’effet inhibiteur d’un produit liquide à base de Bacillus contre Salmonella Typhimurium dans un système in vitro reproduisant en partie le microbiote intestinal du porc. Dans un premier temps, l’effet antibactérien du produit a été testé contre plusieurs bactéries, dont S. Typhimurium, de manière individuelle avec deux méthodes différentes : la méthode de diffusion sur disque et la méthode en bouillon. Le produit probiotique a été séparé en deux phases afin de mesurer l’effet du surnageant et du culot par ces méthodes. Les résultats provenant de la diffusion sur disque ont montré une inhibition de toutes les bactéries testées, mis à part le culot contenant les bactéries probiotiques Bacillus qui n’a pas montré d’effets contre S. Typhimurium. Les essais en bouillon ont montré une inhibition de Salmonella en 10 minutes et 6 heures pour des concentrations de Salmonella de 103 et 106 UFC respectivement. Dans un deuxième temps, des essais en bioréacteur ont été réalisés afin de mesurer l’effet inhibiteur du produit à base de Bacillus sur une communauté microbienne complexe, maintenue dans un bioréacteur, provenant du côlon de porcelets et qui a été inoculée avec S. Typhimurium. Deux modes d’administration du probiotique ont été testés : une dose quotidienne et une dose en continu. Des échantillons ont été récoltés pour mesurer les changements de la composition du microbiote associés à la présence du probiotique à T0, T24, T48, T72, T96 et T120 heures. Les résultats de cette phase du projet ont montré une diminution de Salmonella, une augmentation des bactéries totales et une modulation du microbiote (diversité alpha et bêta) pour les deux modes d’administration (p < 0,05). Le traitement en continu a été associé à plusieurs modifications significatives dans la composition du microbiote (p < 0,05). L’énergie, les protéines brutes et les acides gras à chaine courte (AGCCs) ont été quantifiés pour mesurer l’activité de ce microbiote. Une diminution de la concentration totale (mM/ml) des AGCCs, de l’acétate et une augmentation en proportion du propionate ont été observées (p < 0,05). Cette étude a permis de démontrer l’effet inhibiteur du produit à base de Bacillus sur Salmonella dans un contexte de communauté microbienne complexe en plus de montrer son potentiel en tant que modulateur du microbiote intestinal porcin. / Salmonella is a zoonotic bacteria usually associated with asymptomatic carriage in pigs. Humans can become infected primarily through the consumption of contaminated pork products, which can cause gastroenteritis. Sometimes, complications can have serious consequences. Several methods are currently used to control Salmonella on the farm, but their effectiveness varies. Probiotics have been documented as an interesting alternative to antimicrobials, especially Bacillus spp. Some studies report the effectiveness of Bacillus against Salmonella, as well as their ability to improve the digestive health of pigs partly due to their high production of enzymes. This project aims to characterize the inhibitory effect of a liquid product based on Bacillus against Salmonella Typhimurium in an in vitro system partially reproducing the intestinal microbiota of pigs. Initially, the antibacterial effect of the product was tested against several bacteria, including S. Typhimurium, individually using two different methods: the disk diffusion method and the broth method. The product was separated into two phases to measure the effect of the supernatant and the pellet by these methods. Results from the disk diffusion showed inhibition of all tested bacteria except for the pellet containing Bacillus probiotic bacteria, which showed no effects against S. Typhimurium. Broth assays showed inhibition of Salmonella at 10 minutes and 6 hours for Salmonella concentrations of 103 and 106 CFU, respectively. Secondly, bioreactor essays were conducted to measure the inhibitory effect of the Bacillus-based product on a complex microbial community maintained in a bioreactor, originating from piglet colon and inoculated with S. Typhimurium. Two probiotic administration modes were tested: daily dose and continuous dose. Samples were collected to measure changes in microbiota composition associated with the presence of the probiotic at T0, T24, T48, T72, T96, and T120 hours. Results from this phase of the project showed a decrease in Salmonella, an increase in total bacteria, and modulation of the microbiota (alpha and beta diversity) for both administration modes (p < 0.05). Continuous treatment was associated with several significant modifications in microbiota composition (p < 0.05). Energy, crude proteins, and short-chain fatty acids (SCFAs) were quantified to measure the activity of this microbiota. A decrease in the total concentration (mM/ml) of SCFAs, acetate, and an increase in propionate proportion were observed (p < 0.05). This study demonstrated the inhibitory effect of the Bacillus-based product on Salmonella in a complex microbial community context, as well as its potential as a modulator of the porcine intestinal microbiota.

Durante la mia tesi di dottorato ho selezionato nuovi potenziali ceppi probiotici, combinando l'approccio convenzionale con l’utilizzo di piattaforme di nuova concezione. Mi sono concentrata inizialmente sul cosiddetto "screening tradizionale" finalizzato all'isolamento di nuovi ceppi batterici di lattobacilli e bifidobatteri e alla valutazione della loro sicurezza per il consumo umano e della loro efficacia. I ceppi selezionati sono stati quindi sottoposti ad uno screening più specifico, a seconda dell'applicazione a cui sarebbero stati destinati. In questa fase sono stati utilizzati sia test in vitro che modelli animali, al fine di valutare l'applicabilità dei ceppi di recente selezionati come probiotici per la promozione della salute umana e il loro possibile impiego in campo alimentare. Ho valutato il potenziale utilizzo dei ceppi nell’integrazione alimentare di soggetti che seguono diete ad alto contenuto proteico per ridurre il rischio di accumulo intestinale di ammine biogene, e ho individuato un ceppo di Lactobacillus con presunta attività ammino-degradativa. L'obiettivo principale di un’altra attività di screening è stato lo studio degli effetti immunomodulanti di nuovi ceppi: combinazioni di probiotici sono risultati buoni candidati per il trattamento delle malattie infiammatorie e autoimmuni (miastenia grave e sclerosi multipla) nel modello di topo. Infine, i ceppi sono stati sottoposti a screening per una potenziale applicazione in campo alimentare, finalizzata ad indagare la possibilità di produrre formulazioni di probiotici “atomizzati” da utilizzare insieme alla base commerciale del gelato. / During my PhD thesis I screened new potential probiotic strains by combining conventional approach to newly designed platforms. I focused first on the so-called "conventional screening” aimed to the isolation of new bacterial strains of lactobacilli and bifidobacteria and to assess their safety for human consumption and their efficacy by in-vitro methods. Selected strains were then submitted to a targeted screening by specifically designed models, depending on the application to which they would be destined. These models combined in vitro tests and animal models in order to assess the applicability of newly selected strains as probiotics for the promotion of human health and their possible use in food field. I evaluated the potential use of strains in the food supplementation of subjects that follow high-protein diets to reduce the risk of intestinal accumulation of biogenic amines, and I identified a strain of Lactobacillus with alleged amino degradative activity. The main objective of another screening activity was the study of the immunoregulatory effects of new strains: combinations of probiotics resulted good promising candidates for the treatment of inflammatory and autoimmune diseases (myasthenia gravis and multiple sclerosis) in rat model. Finally, strains were screened for a potential application in food field, in order to investigate the possibility of producing spray-dried probiotic formulations to be used together with commercial ice-cream bases.

Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The equine gastro-intestinal tract (GIT) is a relatively unexplored niche concerning the presence of natural microbiota. Studies have shown that disruption of the microbial population naturally present in the GIT leads to the onset of several forms of gastro-intestinal disorders. To maintain a balanced microbiota, probiotic bacteria need to be administered at specific levels. Beneficial microorganisms assist with digestion of the feed, absorption of nutrients from the GIT, strengthens the immune system and improves the animal‟s growth. Various combinations of lactic acid bacteria (LAB) have been administered to horses, but have failed to benefit the host in any of the latter criteria. The screening for alternative strains with probiotic properties is thus necessary. Two strains (Lactobacillus equigenerosi Le1 and Lactobacillus reuteri Lr1) were originally isolated from horse faeces. Lactobacillus plantarum 423 and Enterococcus mundtii ST4SA, both bacteriocin-producing strains, were isolated from sorghum beer and soy beans, respectively. All four strains survived growth at acidic conditions (pH 3) and the presence of 0.5%, 1.0% and 1.5% (w/v) bile salts. L. reuteri Lr1 was the most resistant to these conditions. All strains adhered to buccal (cheek) epithelium cells sampled from horses. L. equigenerosi Le1 and E. mundtii ST4SA, however, invaded the cells, but without visible signs of disrupting the cells. None of the strains contained genes encoding adhesion to collagen (Ace), resistance to vancomycin A, B and C, or, production of aggregation substance (AS), cytolysin (Cyl) and, non-cytolysin (β hemolysin III), suggesting that they are non-virulent. Of all strains, L. equigenerosi Le1 competed the best with Clostridium sp. C6 for adherence to epithelial cells. L. equigenerosi Le1 and L. reuteri Lr1, showed the highest level of co-aggregation with Clostridium sp. C6. When the four strains were administered to horses over a period of 10 days, L. reuteri Lr1 was retained the longest (8 days) in the GIT. The numbers of viable cells of Clostridium spp. and Salmonella spp. remained constant during administration of the four strains. Blood analyses showed no negative effects from administering the strains. Total white blood cell counts remained unchanged. However, a small but tentative increase in neutrophil and eosinophil cell numbers has been recorded, suggesting that the LAB may have elicited a mild, transient, intolerance reaction. The glucose, lactate and urea levels decreased during administration with the four LAB strains. / AFRIKAANSE OPSOMMING: Die spysverteringstelsel (SVS) van die perd is 'n relatief onbekende nis wat die voorkoms van natuurlike mikrobiota betref. Studies het getoon dat versteuring van die natuurlike mikrobiese populasie in die SVS aanleiding kan gee tot die ontwikkeling van menige vorms van gastro-intestinale ongesteldhede. Om 'n gebalanseerde mikrobiota te verseker, moet probiotiese bakterieë teen 'n spesifieke vlak toegedien word. Voordelige mikroorganismes bevorder vertering en absorpsie van nutriënte vanaf die SVS, versterk die immuunsisteem en bevorder die groei van die dier. Verskeie kombinasies van melksuurbakterieë is reeds aan perde toegedien, maar sonder ooglopende voordele vir die dier. Die soeke na alternatiewe stamme met probiotiese eienskappe is dus noodsaaklik. Twee melksuurbakterieë (Lactobacillus equigenerosi Le1 en Lactobacillus reuteri Lr1) is oorspronklik uit perdemis geïsoleer. Lactobacillus plantarum 423 en Enterococcus mundtii ST4SA, beide bakteriosienproduserende stamme, is afsonderlik van sorghumbier en sojabone geïsoleer. Al vier spesies groei by lae pH (pH 3) en in die teenwoordigheid van 0.5%, 1.0% en 1.5% (m/v) galsoute. L. reuteri Lr1 is die mees bestand onder hierdie toestande. Al vier stamme het aan wang epiteelselle van perde geheg. L. equigenerosi Le1 en E. mundtii ST4SA het egter die epiteelselle binnegedring, maar sonder opsigtelike vernietiging van die selle. Nie een van die stamme besit gene wat kodeer vir aanhegting aan kollageen (Ace), bestandheid teen vankomisien A, B en C, of produksie van, sel-aggregasie (AS), sitolisien (Cyl) en nie-sitolisien (β-hemolisien III), wat daarop dui dat hulle nie-virulent is. Van al die stamme het L. equigenerosi Le1 die beste met Clostridium sp. C6 vir aanhegting aan epiteelselle gekompeteer. L. equigenerosi Le1 en L. reuteri Lr1, het die beste vlak van ko-aggregasie met Clostridium sp. C6 getoon. Met die toediening van 'n kombinasie van die vier stamme aan die perde oor 'n periode van 10 dae, het L. reuteri Lr1 die langste retensie (8 dae) in die SVS getoon. Die aantal lewende selle van Clostridium spp. en Salmonella spp. het konstant gebly tydens toediening van die vier stamme. Toediening van die vier stamme het geen negatiewe effek getoon met resultate verkry van bloed analises nie. Die totale witbloed seltellings het onveranderd gebly. 'n Klein, maar tentatiewe, toename in neutrofiel- en eosinofiel selgetalle is waargeneem, wat daarop dui dat die melksuurbakterieë 'n geringe allergiese reaksie teweeggebring het. Die glukose, laktaat en ureum vlakke het gedaal tydens die toediening van die vier melksuurbakterie stamme.

Thesis (MScAgric)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Different substances were evaluated and compared to an antibiotic, in terms of their effect on nitrogen - and amino acid digestibilities. Two digestibility trials and one performance trial were conducted. Trials one and two apparent nitrogen (AND)- and amino acid (AAD) digestibilities were determined from digesta collected at the terminal ileum (ileal digestibility method). In Trial 3 the substances were evaluated in terms of their potential to improve production performance. Broilers were fed a maizesoya based diet throughout the three trails. In the first trial, garlic and a commercial prebiotic (Bio-Mos®), were tested and compared in terms of AND and AAD, to an antibiotic (doxycyclin, Doxyvete-SOS). A starter and finisher diet were fed as either mash or pellets. The garlic was included at 8g/kg, 13g/kg and 18g/kg to the starter and finisher diets. Bio-Mos® was added at 1g/kg, 2g/kg and 3g/kg to the starter diet, and 0.5g/kg, 1g/kg and 1.5g/kg to the finisher diet. The doxycyclin was added at 0.3 g/kg. None of the treatments had any beneficial effects in terms of AND. Feeding a pellet seem to have some negative effects in terms of AND. In general most of the treatments did not show any improvement in AAD at any determination period (day 21, 28 or 35). At day 21 and day 35, the mash diet supplemented with 18g/kg garlic had a negative effect on AAD, when compared to the negative and positive control. It doesn’t seem that feeding either a mash or a pellet had an influence on the effects exerted by the different treatments. In the second trial the influence of Bio-Mos®, a blend of organic acids, probiotics and electrolytes (Acid-Pak 4-way®) and a medium-chain triglyceride (MCT) were evaluated and compared in terms of AAD and AND, to the effect of an antibiotic, doxycyclin. The starter and finisher diets were fed as a mash. Bio-Mos® was included at 1g/kg, 2g/kg, and 3g/kg in the starter diet, and at 0.5g/kg, 1g/kg, 1.5g/kg in the finisher diet, respectively. Acid-Pak 4-way® was included at 0.4g/kg, 1g/kg and 1.6g/kg for both the starter and finisher diets. Medium-chain triglycerides (MCT) were allocated at 3g/kg, 3.6g/kg, 4.2g/kg for the starter diet, and 2.1g/kg, 2.7g/kg and 3.4g/kg for the finisher diet. An antibiotic, doxycyclin, was included at 0.3 g/kg. With AND, no treatment had any significant effect for the entire experimental period. At day 21, the treatment supplemented with MCT (3.4g/kg) had the most significant beneficial effect on AAD, when compared to the negative- and positive controls, as it increased AAD for the majority of the amino acids. The treatment with Acid-Pak 4-way® (1g/kg) had the most significant negative effect on AAD when compared to the positive control. At day 28, the treatments with Bio-Mos® (0.5g/kg and 1.5g/kg) and Acid-Pak 4-way® (0.4g/kg) had the most significant beneficial effect on AAD when compared to the positive control. It increased AAD for more than half of the 17 amino acids evaluated. The treatment supplemented with MCT (2.7g/kg) has shown the most significant negative effect on AAD, when compared to the positive control. In the third trial the effect of Bio-Mos®, Acid-Pak 4-way® and MCT on production performance was evaluated, and compared to the effects of the presence or absence of doxycyclin. Body weight (BW), body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were measured. The starter and finisher diets were fed as a mash. Bio-Mos®, MCT and Acid-Pak 4-way® were included at 3.0g/kg, 4.2g/kg and 1.6g/kg, respectively in the starter and finisher diets. Birds were weighed (per pen) on arrival and on days 7, 14, 21, 28, 35. Feed intake (FI) per pen was measured at days 7, 14, 21, 28 and 35, and mortality was recorded daily. In terms of BWG, Acid-Pak 4-way® had a higher BWG, when compared to the negative control, Bio-Mos® and MCT. It can be concluded that Bio-Mos®, Acid-Pak 4-way®, as well as MCT can be a possible alternatives to antibiotic supplementation. These three treatments did not necessary prove to be more effective than antibiotics, but are definitely competitive alternatives. / AFRIKAANSE OPSOMMING: Verskillende behandelings is geëvalueer en vergelyk met ‘n antimikrobiese produk, in terme van hul uitwerking op stikstof - en aminosuur verteerbaarhede. Twee verteringstudies en produksieprestasie studie is uitgevoer. In die eerste twee studies is die skynbare stikstof (AND)- en aminosuur (AAD) verteringskoöeffisiënte bepaal deur gebruik te maak van digesta wat by die terminale ileum ingesamel is (ileale verteringsmetode). In die derde studie is die produksie prestasie van braaikuikens op ‘n gebalanseerde metaboliseerbare energie (AME) rantsoen, soos beïnvloed deur die verskillende behandelings, geëvalueer. In die eerste studie is knoffel en ‘n kommersiële prebiotikum (Bio-Mos®) geëvalueer en met ‘n antibiotikum (doksisiklien, Doxyveto-SOS) in terme van AND en AAD vergelyk. Beginner- en afrondingsrantsoene is as ‘n meel of pille gevoer. Die knoffel is teen 8g/kg, 13g/kg en 18g/kg in die rantsoen ingesluit. Bio-Mos® is teen 1g/kg, 2g/kg en 3g/kg in die beginner rantsoen en teen 0.5g/kg, 1g/kg en 1.5g/kg in die afrondingsrantsoen, ingesluit. Die antibiotikum is teen 0.3g/kg in beide rantsoene ingesluit. Geen van die behandelings het enige positiewe invloed op AND gehad nie. Deur ‘n verpilde rantsoen te voer het sekere negatiewe invloed op AND gehad. Oor die algemeen het geen behandelings enige positiewe invloed op AAD gehad nie. Op dag 21 en 35 het die insluiting van knoffel teen 18g/kg in ’n meel rantsoen ’n negatiewe invloed op AAD gehad, wanneer dit met die negatiewe- en positiewe kontroles vergelyk is. Dit blyk nie dat om ‘n pil of meel te voer enige invloed op die invloede van die verskillende behandelings gehad het nie. In die tweede studie is Bio-Mos®, ‘n organiese suur (Acid-Pak 4-way®) en ‘n medium-ketting trigliseried (MCT) geëvalueer en met ‘n antbiotikum, doksisiklien (Doxyveto-SOS) in terme van AND en AAD, vergelyk. Beginner- en afrondingsrantsoene is gevoer as ‘n meel. Bio-Mos® is teen 1g/kg, 2g/kg, and 3g/kg in die beginner rantsoen en teen 0.5g/kg, 1g/kg, 1.5g/kg in die afrondingsrantsoen, ingesluit. Acid-Pak 4-way® is teen 0.4g/kg, 1g/kg en 1.6g/kg vir die beginner –en afrondingsrantsoene ingesluit. Die MCT is teen 3g/kg, 3.6g/kg, 4.2g/kg in die beginner rantsoen en teen 2.1g/kg, 2.7g/kg en 3.4g/kg in die afrondingsrantsoen ingesluit. Die antibiotikum is ingesluit teen 0.3g/kg. Geen behandelings het enige betekenisvolle invloed in terme van AND gehad nie. Op dag 21 het MCT (3.4g/kg), in vergelyking met die negatiewe- en positiewe kontrole, die grootste positiewe invloed op AAD gehad. Acid-Pak 4-way® (1g/kg) het, in vergelyking met die positiewe kontrole, ‘n positiewe invloed gehad op AAD. Op dag 28, het Bio-Mos® (0.5g/kg en 1.5g/kg) en Acid-Pak 4-way® (0.4g/kg) die grootste positiewe invloed op AAD gehad. Die behandeling met MCT (2.7g/kg) het die mees negatiewe invloed op AAD gehad. In die derde studie is die insluiting van Bio-Mos®, Acid-Pak 4-way® en MCT getoets om die invloed op braaikuiken produksie prestasie te evalueer, en te vergelyk met die invloed van die insluiting of afwesigheid van ‘n antibiotikum. Liggaamsmassa (BW), liggaamsmassa toename (BWG), voerinname (FI) en voeromsetverhouding (FCR) is gemeet. Beginner- en afrondings rantsoene is gevoer as ‘n meel. Bio-Mos®, MCT en Acid-Pak 4-way® is onderskeidelik teen 3.0g/kg, 4,2g/kg en 1.6g/kg in die rantsoen ingesluit. Die kuikens is met aankoms (per hok) geweeg, asook op dae 7, 14, 21, 28, 35. Voerinname per hok is gemeet op dae 7, 14, 21, 28 en 35. Mortaliteite is daagliks aangeteken. Die insluiting van Acid-Pak 4-way® het in vergelyking met die negatiewe kontrole, Bio-Mos® en MCT insluiting ‘n hoër BWG tot gevolg gehad. Die gevolgtrekking wat gemaak kan word is dat Bio-Mos®, Acid-Pak 4-way® en MCT gebruik kan word as ‘n moontlike alternatief vir antibiotika insluiting. Hierdie drie behandelings was nie noodwending meer effektief as die antibiotika nie, maar het wel bewys dat dit kompeterende alternatiewe is.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction: An association between maternal human immunodeficiency virus (HIV) infection and Necrotizing Enterocolitis (NEC) in preterm infants has been reported. The impact of probiotics in an HIV-exposed very low birth weight (VLBW) infant on the occurrence of NEC is uncertain at present; however it is known that probiotics have protective effects against inflammation and prevent NEC. Postnatal growth restriction is a major issue in preterm, especially extremely-low-birth-weight (ELBW) infants and probiotics have been found to improve feeding tolerance in preterm infants. Human milk oligosaccharides (HMO) also known as the prebiotics of human milk, are known to have bifidogenic and anti-adhesive effects. Infants that receive human milk show a reduced incidence of NEC compared to those who receive infant formula. Very little is known about the composition of breast milk in the HIV-infected mother. Objective: The primary objective of the study was to assess the effect of probiotics on the incidence and severity of NEC in high-risk infants born to HIV-positive and HIV-negative women. The secondary objectives were to assess the effect of probiotic administration on feeding tolerance and growth outcomes of HIV-exposed but uninfected preterm infants, to describe the HMO composition of HIV-infected mothers breast milk and lastly to determine if HMO composition affects the incidence of NEC in HIV-exposed preterm very low birth weight infants. Patients and Methods: A randomized, double blind, placebo controlled trial was conducted for the period July 2011 to August 2012. HIV-exposed and HIV-unexposed premature (<34 weeks gestation) infants with a birth weight of ≥500g and ≤1250g were randomized to receive either a probiotic or a placebo. The probiotic consisted of 1x109 CFU, L. rhamnosus GG and B. infantis per day and was administered for 28 days. NEC was graded according to Bell’s criteria. Anthropometrical parameters and daily intakes were monitored. Breats milk samples were analysed for oligosaccharide content. Results: 74 HIV-exposed and 110 HIV-unexposed infants were enrolled and randomized (mean birth-weight, 987g; mean gestational 28.7 weeks). The incidence of death and NEC did not differ significantly between the HIV-exposed and unexposed groups but a significantly higher NEC incidence was found in the control group. There was no difference in the average daily weight gain for treatment groups or HIV exposure. The HIV-exposed group achieved significantly higher z-scores for length and head circumference at day 28 than the unexposed group (p<0.01 and p=0.03, respectively). There were no differences in the incidence of any signs of feeding intolerance and abdominal distension between the groups. Our results show significantly higher absolute concentrations of 2’-fucosyllactose, laco-N-tetraose and lacto-N-fucopentaose 1 and higher relative abundance of 3’-sialyllactose, difucosyl-lacto-N-tetraose and fucosyl-disialyllacto-N-hexaose in HIV-infected compared to -uninfected Secretor women. DSLNT concentrations were significantly lower in the breast milk of mothers whose infants developed NEC compared to infants without NEC. Conclusion: Probiotic supplementation reduced the incidence of NEC in the premature infants; however results failed to show a lower incidence of NEC in HIV-exposed premature infants. Probiotic supplementation did not affect growth outcomes or the incidence of any signs of feeding intolerance in HIV-exposure. The data confirms previous reports that HIV-infected mothers have higher 3’sialyllactose milk concentrations. Most intriguing though, the data also indicates that low levels of DSLNT in the mother’s milk increase the infant’s risk for NEC, which is in accordance with results from previously published animal studies and warrants further investigation. / AFRIKAANSE OPSOMMING: Inleiding: ʼn Verwantskap tussen moederlike menslike immuniteitsgebreksvirus (MIV) en nekrotiserende enterokolitis (NEK) in premature babas is aangemeld. Die impak van probiotika in ʼn MIV-blootgestelde baie lae geboortemassa (BLGM) baba op die voorkoms van NEK is tans nog onseker, maar dit is wel bekend dat probiotika ʼn beskermende effek het teen inflammasie en die voorkoms van NEK. Nageboortelike groei beperkings is ʼn groot probleem in premature, veral ekstreme lae geboortemassa (ELGM) babas. Daar is gevind dat probiotika voeding toleransie in premature babas kan verbeter. Menslike melk oligosakkariede (MMO), ook bekend as die prebiotika van menslike melk, is bekend om bifidogeniese en anti-kleef effekte te hê. Babas wat moedersmelk ontvang toon ʼn verlaagde voorkoms van NEK in vergelyking met diegene wat baba formule melk ontvang. Baie min inligting is bekend oor die samestelling van borsmelk in die MIV-positiewe moeder. Doel: Die primêre doel van die studie was om die effek van probiotika op die voorkoms en die graad van NEK in hoë risiko babas van MIV-positiewe en MIV-negatiewe vroue te bepaal. Die sekondêre doelwitte was om die effek van probiotika op voeding verdraagsaamheid en groei uitkomste van MIV-blootgestelde, maar nie- geinfekteerde premature babas te evalueer sowel as die MMO samestelling van MIV-positiewe moeders se borsmelk te beskryf en laastens om die invloed van die MMO samestelling op die voorkoms van NEK in baie lae geboortegewig MIV-blootgestelde premature babas te beskryf. Pasiënte en Metodes: ʼn Gerandomiseerde, dubbelblinde, plasebo-beheerde studie is vir die tydperk Julie 2011 tot Augustus 2012 onderneem. MIV-blootgestelde en nie-blootgestelde premature (<34 weke) babas met 'n geboorte gewig van ≥500g en ≤1250g was ewekansig verdeel om probiotika of plasebo te ontvang. Die probiotika het bestaan uit 1x109 kolonie vormende eenhede, L. rhamnosus GG en B. infantis per dag en is toegedien vir 28 dae. NEK is gegradeer volgens Bell se kriteria. Antropometriese parameters en daaglikse inname is gemonitor. Borsmelk monsters is geanaliseer vir oligosakkaried inhoud. Resultate: 74 MIV-blootgestelde en 110 MIV-nie-blootgestelde babas is ingesluit en ewekansig ingedeel (gemiddelde geboorte gewig, 987g, gemiddelde gestasie 28,7 weke). Die voorkoms van die sterftes en NEK het nie beduidend verskil tussen die MIV-blootgestelde en nie-blootgestelde groepe nie, maar 'n beduidende verskil is gevind vir NEK voorkoms tussen die studie en die kontrole groep. Daar was geen verskil in die gemiddelde daaglikse gewigstoename tussen die behandelings groepe of MIV-blootstelling nie. Die MIV-blootgestelde groep het beduidend hoër z-tellings vir lengte en kopomtrek op dag 28 getoon teenoor die nie-blootgestelde groep (p <0.01 en p = 0,03, onderskeidelik). Daar was geen verskille in die voorkoms van voeding onverdraagsaamheid en abdominale distensie tussen die twee groepe nie. Ons resultate dui op aansienlik hoër absolute konsentrasies van 2'-fucosyllactose, laco-N-tetraose en lakto-N-fucopentaose 1 en hoër relatiewe voorkoms van 3'-sialyllactose, difucosyl-lakto-N-tetraose en fucosyl-disialyllacto-N-hexaose in MIV-positiewe vroue in vergelyking met-negatiewe Sekretor vroue. DSLNT konsentrasies was aansienlik laer in die melk van moeders wie se babas NEK ontwikkel het in vergelyking met babas sonder NEK. Gevolgtrekking: Probiotika aanvullings verminder die voorkoms van NEK in premature babas, maar die resultate kon nie ʼn laer voorkoms van NEK in MIV-blootgestelde premature babas bewys nie. Probiotiese aanvulling het geen invloed op groei uitkomste of die voorkoms van voeding onverdraagsaamheid in MIV-blootstelling getoon nie. Die data bevestig vorige verslae wat aandui dat MIV-besmette moeders hoër 3'sialyllactose borsmelk konsentrasies het. ʼn Interessante aspek is dat lae vlakke van DSLNT in die moeder se melk beduidend is van ʼn verhoogde risiko vir NEK, wat in ooreenstemming is met die resultate uit voorheen gepubliseerde dier studies en regverdig verdere ondersoeke.

Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: The tolerance of Enterococcus mundtii ST4SA to stressful gastro-intestinal conditions in humans and animals is vital to its success as a probiotic. The need for new effective probiotics with stronger inhibitory (bacteriocin) activity has arisen due to the increasing number of antibiotic resistant pathogens. Enterococci are used in the fermentation of sausages and olives, cheese making and as probiotics. Their role as opportunistic pathogens in humans makes them a controversial probiotic (Moreno et al., 2005). Enterococci occur naturally in the gastro-intestinal tract which renders them intrinsic acid and bile resistance characteristics. E. mundtii ST4SA produces a 3950 Da broad-spectrum antibacterial peptide active against Gram-positive and Gram-negative bacteria, and viruses. The bacteria include Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae and Staphylococcus aureus. E. mundtii ST4SA inactivates the herpes simplex viruses HSV-1 (strain F) and HSV-2 (strain G), a measles virus (strain MV/BRAZIL/001/91, an attenuated strain of MV), and a polio virus (PV3, strain Sabin). This study focuses on the genetic stability of E. mundtii ST4SA genes when exposed to stress factors in the human and animal gastrointestinal tract. Based on results obtained by real-time PCR, the expression of genes encoding bacST4SA, RecA, GroES and 23S rRNA by E. mundtii ST4SA were not affected when the cells were exposed to acid, bile and pancreatic juice. This suggests that these genes of E. mundtii ST4SA will remain stable in the intestine. This could indicate that other genes of E. mundtii ST4SA could remain stable in the host. Further studies on the stability of genes encoding antibiotic resistance and virulence factors should be conducted to determine their stability and expression in the host in stress conditions. Concluded from this study, E. mundtii ST4SA is an excellent probiotic strain. / AFRIKAANSE OPSOMMING: Enterococcus mundtii ST4SA se weerstandsvermoë teen stresvolle gastrointestinale kondisies is essensieel vir die sukses van hierdie organisme as ‘n probiotikum. Die aanvraag vir nuwe, meer effektiewe probiotika met sterker inhibitoriese (bakteriosien) aktiwiteit is as gevolg van die toename in antibiotikum weerstandbiedende patogene. Enterococci word algemeen gebruik as probiotika, sowel as in die fermentasie van worse, olywe en kaas. Hulle rol as oppertunistiese patogene in mense veroorsaak kontroversie as gevolg van hul toenemende gebruik as probiotika. Enterococci is deel van die natuurlike mikroflora in die gastrointestinale weg van mense en diere. Dit verleen aan hierdie spesies ‘n natuurlike weerstandsvermoë teen maagsure, galsoute en pankreatiese afskeidings. E. mundtii ST4SA produseer ‘n 3950 Da wye spektrum anti-bakteriese peptied, aktief teen Gram positiewe en Gram negatiewe bakterieë sowel as virusse. Hierdie bakterieë sluit Enterococcus faecalis, Streptococcus spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae en Staphylococcus aureus in. E. mundtii ST4SA inaktiveer die herpes simpleks virus HSV-1 en HSV-2, ‘n masels virus (MV/BRAZIL/001/91), en ‘n polio virus (PV3, stam Sabin). Hierdie studie fokus op die genetiese stabiliteit van E. mundtii ST4SA gene, wanneer hulle blootgestel word aan stress faktore in die mens en dier gastrointestinale weg. “Intydse” PKR data gebasseer op die uitdrukking van die bacST4SA, RecA, GroES en 23S rRNA gene in stresvolle kondisies dui aan dat E. mundtii ST4SA nie geaffekteer word wanneer die sel blootgestel word aan suur, gal en pankreatiese vloeistowwe nie. Hierdie resultate dui aan dat hierdie gene van E. mundtii ST4SA stabiel sal bly in die intestinale weg van die mens en dier. Dit kan aandui dat ander gene van E. mundtii ST4SA soos die wat kodeer vir virulensie faktore en antibiotikum se weerstandsvermoë stabiel mag bly in die gasheer. Verdere studies wat fokus op die stabiliteit van gene wat kodeer vir antibiotikum weerstandbiedendheid en virulensie faktore moet uitgevoer word om hulle stabiliteit en uitdrukking in die gasheer te bepaal. Bevindings van hierdie studie dui aan dat E. mundtii ST4SA goeie potensiaal het as ‘n probiotikum.