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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Avaliação de efeitos fisiológicos da fração fibra alimentar dos grãos de amaranto (Amaranthus cruentus L.) e linhaça (Linum usitatissimun L). / Evaluation of dietary fiber physiological effects of amaranth (Amaranthus cruentus) and flaxseed (Linum usitatissimum L.) grains.

Andrea Carvalheiro Guerra Matias 12 February 2008 (has links)
Os grãos de linhaça e amaranto recebem grande atenção da população em decorrência de suas alegações nutricionais e funcionais à saúde. Uma vez que estes grãos apresentam significativos teores de fibras alimentares (28 e 10%, respectivamente), os efeitos fisiológicos benéficos associados a estas frações foram investigados por meio de parâmetros do metabolismo colônico (fermentativos) e lipídico em ensaio biológico com ratos (Wistar), divididos em quatro grupos (n=12) durante 28 dias. As dietas dos grupos Referência e Controle apresentaram 7% (p/p) de celulose, e as dietas dos grupos experimentais foram formuladas com: farinha desengordurada de linhaça; amaranto extrusado, de modo que apresentassem 7% de fibra alimentar (FA). Com exceção da dieta do grupo Referência, as demais apresentaram 0,5% de colesterol (p/p). Foram observados para os grupos Linhaça e Amaranto: aumento do peso do ceco e conteúdo; aumento da massa fecal úmida; aumento dos ácidos graxos de cadeia curta (AGCC) e diminuição do pH no conteúdo do ceco, indicando fermentação colônica. Os animais do grupo Linhaça apresentaram menor peso e colesterol hepático, porém, nenhuma alteração no colesterol plasmático e na excreção de colesterol e ácidos biliares nas fezes. Já os animais do grupo Amaranto apresentaram menor peso hepático, porém, nenhuma alteração do colesterol total do órgão. Neste grupo também não foi observada redução do colesterol plasmático, acompanhada do aumento da excreção do colesterol e redução dos ácidos biliares nas fezes. Sugere-se que o trofismo da parede do ceco está relacionado à produção de ácido butírico, principal substrato energético dos colonócitos, que contribui para uma mucosa mais resistente a patógenos e carcinógenos. O mecanismo envolvido no efeito hepatoprotetor observado no grupo Linhaça pode estar relacionado à produção de ácido propiônico no cólon, uma vez que a literatura sugere que o mesmo pode estar envolvido na inibição da HMG-CoA redutase. Desconhecem-se, até o momento, os mecanismos que promoveram a menor excreção de ácidos biliares nas fezes no grupo Amaranto. De qualquer modo, as FAs do grão de linhaça e amaranto não foram capazes de promover efeito hipercolesterolemiante nas condições em que foi realizado este estudo. Conclui-se que as frações indigeríveis da linhaça e amaranto são benéficas para a saúde da mucosa intestinal. / The flaxseed and amaranth grains are recognized by their nutritional and functional health attributes. These grains have significant contents of dietary fiber (28 and 10%, respectively), and the physiological effects related to these fractions were investigated by colonic fermentative and lipid metabolism parameters with rats (Wistar) distributed in five groups (n=12) during twenty-eight days. The diets of the Reference and Control groups contained 7% (w/w) of cellulose and the diets of the experimental groups were formulated with: defatted flaxseed flour and defatted extruded amaranth, in order to provide 7% dietary fiber (DF). With the exception of the Reference, the other diets received 0,5% cholesterol. The Flaxseed and Amaranth groups compared to the Control showed: greater weight of caecum and its contents; greater weight of feces (wet mass); increase of short chain fatty acids (SCFA) concentration and decrease of pH of cecal content, indicating colonic fermentation. The Flaxseed group showed lower liver hepatic weight and cholesterol, but no changes in plasmatic cholesterol, cholesterol fecal excretion, or bile acids fecal excretion. The Amaranth group exhibited lesser hepatic weight, along with no changes on hepatic cholesterol. Also, no plasma cholesterol reduction was observed, with the increase of fecal cholesterol excretion and decrease in fecal bile acid excretion. It is suggest that the caecum wall trophism was related to butiric acid production, main energy colonic cell substrate that fosters a more resistant mucosa to pathogens and carcinogens. The mechanism involved in liver protecting effect, observed in the Flaxseed group, could be related to propionic acid production, since that it is suggest in the literature that this fatty acid could be envolved in the HMG-CoA reductase inhibition. Until this moment, the mechanisms that promoted the lesser bile acid excretion by the Amaranth group were not kwon. The DFs of flaxseed and amaranth grains were unable to promote hypocholestelolemic effects under the present assay conditions. It could be concluded that DFs of flaxseed and amaranth grains are beneficial to the health of the intestinal mucosa.
32

Avaliação bioquímica de compostos fenólicos in vitro e biológica do extrato purificado de açaí (Euterpe oleracea) em modelo in vivo de carcinogênese de cólon induzida / Biochemistry evaluation of phenolics in vitro and biologic of açaí (Euterpe oleracea) purified extract in model in vivo of induced colon carcinogenesis

Sampaio, Patrícia Brito, 1980- 24 August 2018 (has links)
Orientador: Gláucia Maria Pastore / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T21:03:57Z (GMT). No. of bitstreams: 1 Sampaio_PatriciaBrito_D.pdf: 2558424 bytes, checksum: 8b7f3f32354ab3697fc45d7d6334e2ec (MD5) Previous issue date: 2014 / Resumo: O açaí (Euterpe oleracea) é um fruto amazônico com elevado teor de compostos fenólicos, principalmente antocianinas, e alta capacidade antioxidante. O consumo médio diário de fenóis, polifenóis e taninos pode variar de menos de 100 mg a mais de 2 g. Mais de 95% deste consumo consegue atingir o cólon e é fermentado pela microflora intestinal, portanto após sua captação através da dieta, grande parte desses compostos sofre transformações pelas bactérias intestinais. Para avaliar a ação bioquímica "in vitro" foram testados 11 (onze) padrões de compostos fenólicos presentes e não presentes no açaí mais o ácido ascórbico como antioxidante de referência, além do extrato purificado de polifenóis do açaí (Amazon Dreams Ltda) contendo 16.000 mg/100g de antocianinas e 47.478 mg de equivalentes de ácido gálico/100g de fenólicos totais. Na análise de potencial redox por voltametria cíclica e capacidade antioxidante ORAC não foi encontrada relação dos valores mais altos com os compostos que apresentaram efeito inibitório nos testes em microplacas com bactérias enteropatogênicas, os quais foram os ácidos fenólicos (cafeíco e gálico) e ácido ascórbico. Porém a delfinidina que teve os maiores valores de MIC encontrados coincidiu também com um alto valor ORAC. Os compostos e extrato estudados não tiveram influência negativa no crescimento dos micro-organismos probióticos (Bifidobacterium animalis subsp. Lactis Bb12®. E Lactobacillus rhamnosus ). A fim de verificar a influência do extrato de açaí em parâmetros biológicos e de prevenção do câncer colorretal, foi utilizado modelo de ratos wistar com câncer de colón induzido por DMH (80 mg/Kg) e tratamento combinado com diferentes concentrações do extrato purificado de açaí (30 mg; 50 mg e 180 mg/Kg de peso animal) por 28 dias. Dentre os parâmetros hematológicos e eletrólitos (Na, Ca e K) não houve alterações importantes. As enzimas hepáticas ALT e GGT apresentaram valores mais baixos nos grupos que consumiram o extrato, mesmo com o uso da droga, em comparação com o controle positivo mostrando que o extrato é bem tolerado e não tóxico. Não foi observado aumento de genotoxicidade através do ensaio cometa ( normal e com enzimas Endo III e FPG), em linfócitos e células do colón nos animais tratados e não tratados com o extrato. Houve menor formação de Focos de Criptas Aberrantes no cólon dos grupos que consumiram as doses baixa e intermediária do extrato. Porém a dosagem de 180 mg/kg pode ter tido ação sinergística com a droga aumentando o número de lesões. Houve significância estatística no aumento da produção dos AGCC (acético, propiônico e capróico) quantificados por GC-FID, em todos os grupos que se alimentaram com o extrato de açaí (p <0.001). A produção de isobutírico foi detectada apenas nesses grupos. Isto demonstra que o consumo de extrato de açaí favoreceu a produção de AGCC, até mesmo nos grupos que utilizaram o DMH / Abstract: Açaí ( Euterpe oleracea) is an Amazonian fruit with a high content of phenolic compounds , especially anthocyanins , and high antioxidant capacity . The average daily consumption of phenols, polyphenols and tannins can range from less than 100 mg to more than 2 g .Over 95% of this consumption can reach the colon and is fermented by the intestinal microflora, therefore, after its capture by diet , most of these compounds undergoes transformations by intestinal bacteria. To assess the biochemical action "in vitro" were tested eleven standards of phenolic compounds present and not present in acai more the ascorbic acid standard as antioxidant reference , in addition to the purified extract of açaí polyphenols ( Amazon Dreams Inc. ) containing 16,000 mg / 100g of anthocyanins and 47,478 mg equivalents of gallic acid/100g of total phenolic . In the analysis of redox potential by cyclic voltammetry and ORAC antioxidant capacity was not found ratio of higher values of compounds and with the inhibitory effect under test in microplate with enteropathogenic bacteria, which was the phenolic acids ( gallic acid and caffeic ) and ascorbic acid. But the delphinidin had the highest MIC values found also coincided with a high ORAC value . The compounds studied had no negative influence on the growth of probiotic micro-organisms (Bifidobacterium animalis subsp. Lactis Bb12®. and Lactobacillus rhamnosus ) . In order to verify the influence of acai extract in biology and prevention of colorectal cancer , we used Wistar rat model with colon cancer induced by DMH ( 80 mg / kg ) and combined treatment with different concentrations of purified extract of açaí (30 mg, 50 mg and 180 mg / kg body weight) for 28 days. Among the hematological parameters and electrolytes (Na, Ca and K ) showed no significant changes . The liver enzymes ALT and GGT exhibited lower values in the groups that consumed the extract, even with the use of the drug , compared with the positive control showed that the extract is well tolerated and not toxic. No increase in genotoxicity was observed by comet assay (normal, Endo III and FPG enzymes ) in lymphocytes and colon cells in the animals treated and not treated with the extract . There was less formation of Aberrant Crypt Foci in the colon of the groups that consumed the low and intermediate doses of the extract. However the dose of 180 mg / kg may have been synergistic action with drugs increasing the number of lesions. There was statistical significance in the increased production of SCFA (acetic,propionic and caproic ) quantified by GC- FID in all groups were fed the extract of acai ( p < 0.001 ) . The production of isobutyric acid was detected only in those groups. This demonstrates that consuming açaí extract favored the production of SCFA, even in groups that used the DMH / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos
33

Avaliação in vitro e in vivo das propriedades funcionais e efeitos prebióticos dos galacto-oligossacarídeos (GOS) = In vitro and in vivo evaluation of the functional properties and prebiotics effects of the galacto-oligosaccharides (GOS) / In vitro and in vivo evaluation of the functional properties and prebiotics effects of the galacto-oligosaccharides (GOS)

Lemos, Adriane Cristina Garcia, 1967 21 August 2018 (has links)
Orientador: Gláucia Maria Pastore / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-21T02:44:12Z (GMT). No. of bitstreams: 1 Lemos_AdrianeCristinaGarcia_D.pdf: 1535863 bytes, checksum: be0f41cf63bbd79b46b680df59cba450 (MD5) Previous issue date: 2012 / Resumo: Galacto-oligosacarídeos (GOS) são prebióticos obtidos via transgalactosilação enzimática da lactose. Dentre os vários benefícios associados ao consumo de GOS destaca-se a capacidade de estimular o crescimento e atividade de bactérias benéficas no cólon. O objetivo deste estudo foi avaliar as propriedades prebióticas dos GOS sintetizados, a partir da lactose, por ß-galactosidase de Scopulariopsis sp. A digestibilidade e a fermentabilidade foram avaliadas in vitro, enquanto os efeitos prebióticos foram avaliados in vivo em um conjunto de experimentos com ratos Wistar. Os resultados observados in vitro demonstraram que os GOS produzidos neste estudo são indigeríveis, altamente fermentáveis e convertidos em ácidos graxos de cadeia curta (acetato, propionato e butirato). Estudos in vivo demonstraram que o consumo de diferentes doses de GOS por 42 dias não produziu efeitos tóxicos nos animais, evidenciado a partir de avaliações clínicas, exames hematológicos, bioquímicos, necroscópicos e histológicos. Os ratos suplementados com GOS apresentaram maior (p<0.05) população cecal de bifidobactérias (log10 10,05 ± 0,27 UFC/g) e lactobacilos (log10 8,92 ± 0,16 UFC/g). Para os ratos não suplementados com GOS estas proporções foram de log10 8,22 ± 0,33 e 7,2 ± 0,15 UFC/g, para bifidobacterias e lactobacilos,respectivamente. Por outro lado, a população de Escherichia coli foi significativamente reduzida (p<0.05), sendo 24,75% menor, quando comparada ao grupo controle sem GOS. Além disso, a fermentação dos GOS pelas bactérias intestinais resultou em um aumento na produção de ácidos graxos de cadeia curta de 2,73 vezes, em relação aos animais sem acréscimo de GOS na dieta.Observou-se, ainda, que o grupo suplementado com GOS apresentou maiores valores de espessura total da mucosa, altura dos vilos e profundidade das criptas,evidenciado pela maior relação altura de vilosidades:profundidade de cripta em relação ao grupo controle / Abstract: Galacto-oligosaccharides (GOS) are prebiotics obtained via transgalactosylation enzymatic of lactose. Among the many benefits associated with consumption of GOS stands the ability to stimulate growth and activity of beneficial bacteria in the colon. The objective of this study was to evaluate the properties of prebiotic GOS synthesized from lactose by ß-galactosidase from Scopulariopsis sp. The digestibility and fermentability were evaluated in vitro, while the prebiotic effects were evaluated in vivo in a series of experiments with Wistar rats. The results observed in vitro showed that the GOS produced by this study are indigestible highly fermentable and converted into short-chain fatty acids (acetate,propionate and butyrate). In vivo studies have showed that consumption of different doses of GOS for 42 days produced no toxic effects in animals, as evidenced from clinical, hematological, biochemical, and histological necropsy. The rats supplemented with GOS had higher (p<0.05) cecal populations of bifidobacteria (log10 10.05 ± 0.27 UFC/g) and lactobacillus (log10 8.92 ± 0.16 UFC/g). For rats not supplemented with GOS these proportions were log10 8.22 ± 0.33 and 7.2 ± 0.15 UFC/g, for bifidobacteria and lactobacillus, respectively.Furthermore, the population of Escherichia coli was significantly reduced (p<0.05) and 24.75% less when compared to controls without GOS. Furthermore, the GOS fermentation by intestinal bacteria resulted in an increase in the production of short chain fatty acids from 2.73 times in compared with those without the addition of GOS diet.It was observed also the supplemented group with GOS showed higher values of total mucosal thickness, villous height and crypt depth, evidenced by the higher ratio of villus height: crypt depth in the control group / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos
34

Prebiotic oligosaccharides and their fermentation products in a novel putative probiotic strain from the genus Weissella.

Santesson, Sara January 2017 (has links)
Our large intestine is like a large metabolic organ colonised by microorganisms. Beneficial probiotic bacteria are of interest since they might metabolise certain prebiotic carbohydrates and produce metabolites that are suggested to promote health and prevent diseases.   Strains of Weissella have proven probiotic properties since they, for example, show ability to metabolise prebiotic oligosaccharides, are resistant to a low pH (pH 2-3) and bile salt. In a previous project, six new strains of Weissella were isolated from Indian fermented food and vegetables, and four of them, including strain 92, were able to ferment xylooligosaccharides and form short chain fatty acids (SCFA), especially acetic acid. This strengthened the probiotic potential of these strains.   The aim of this project was to see if previously untested oligosaccharides (arabinooligosaccharides (AOS), laminarioligosaccharides (LOS) and chitooligosaccharides (COS)) could be metabolised by Weissella strain 92.   This study includes the following steps; cell growth in MRS (De Man, Rogosa and Sharpe) medium on different carbohydrates measured with spectrophotometer, pH measurement (analysing the difference of MRS medium (pH 6.42) pre and post cell growth, where reduced pH indicates acid production), and analysis of fermentation products (including SCFA (short chain fatty acids, e.g. acetic acid, butyric acid, propionic acid), lactic acid and ethanol) with an HPLC (high-performance liquid chromatography) instrument.   This research study has shown that Weissella strain 92 produces acetic and butyric acid as a consequence of use of AOS, LOS and COS, this indicates that the oligosaccharides are prebiotic and emphasizes the probiotic potential of Weissella strain 92.
35

Bioengineered Wheat Arabinoxylan: Fostering Next-Generation Prebiotics Targeting Gut Microbiome and Depression Inversely-Linked Microbes

Njoku, Emmanuel Nnabuike 20 April 2023 (has links)
Various disorders closely linked to gut dysbiosis have been associated with poor dietary patterns. Dietary prebiotic fibers play an essential role in modulating the gut microbiome by enhancing the abundance of beneficial microorganisms and improving the production of short-chain fatty acids. Arabinoxylan (AX) is a major component of most dietary fibers and has been shown to exhibit potential prebiotic properties and modulate gut microbiome composition. This study aimed to investigate the in vitro impact of bioengineered wheat arabinoxylan on depression-inversely linked gut microbes and human gut microbiome diversity and metabolism. This study demonstrates the ability of bioengineered AX to stimulate the growth of depression-inversely linked gut bacterial species (Faecalibacterium prausnitzii and Lacticaseibacillus rhamnosus LGG). On the microbiome composition, the bioengineered AX induced an increased abundance of beneficial bacterial taxa (Bacteroides, Bifidobacterium, Anaerofustis, and Eubacterium) compared to the control and native AX. These effects on microbes translated into significant metabolic activity and produced primary SCFAs (acetate, butyrate, and propionate). The findings from this study suggest that bioengineered wheat arabinoxylan could be considered a promising strategy for fostering next-generation prebiotics targeting depression-inversely linked gut microbes and also supports the structure-function relationship between AX and the human gut microbiome.
36

The effect of phenobarbital treatment on behavioral comorbidities and on the composition and function of the fecal microbiome in dogs with idiopathic epilepsy

Watanangura, Antja, Meller, Sebastian, Suchodolski, Jan S., Pilla, Rachel, Khattab, Mohammad R., Loderstedt, Shenja, Becker, Lisa F., Bathen-Nöthen, Andrea, Mazzuoli-Weber, Gemma, Volk, Holger A. 02 November 2023 (has links)
Phenobarbital (PB) is one of the most important antiseizure drugs (ASDs) to treat canine idiopathic epilepsy (IE). The effect of PB on the taxonomic changes in gastrointestinal microbiota (GIM) and their functions is less known, which may explain parts of its pharmacokinetic and pharmacodynamic properties, especially its antiseizure effect and drug responsiveness or drug resistance as well as its effect on behavioral comorbidities. Fecal samples of 12 dogs with IE were collected prior to the initiation of PB treatment and 90 days after oral PB treatment. The fecal samples were analyzed using shallow DNA shotgun sequencing, real-time polymerase chain reaction (qPCR)-based dysbiosis index (DI), and quantification of short-chain fatty acids (SCFAs). Behavioral comorbidities were evaluated using standardized online questionnaires, namely, a canine behavioral assessment and research questionnaire (cBARQ), canine cognitive dysfunction rating scale (CCDR), and an attention deficit hyperactivity disorder (ADHD) questionnaire. The results revealed no significant changes in alpha and beta diversity or in the DI, whereas only the abundance of Clostridiales was significantly decreased after PB treatment. Fecal SCFA measurement showed a significant increase in total fecal SCFA concentration and the concentrations of propionate and butyrate, while acetate concentrations revealed an upward trend after 90 days of treatment. In addition, the PB-Responder (PB-R) group had significantly higher butyrate levels compared to the PB-Non-Responder (PB-NR) group. Metagenomics of functional pathway genes demonstrated a significant increase in genes in trehalose biosynthesis, ribosomal synthesis, and gluconeogenesis, but a decrease in V-ATPase-related oxidative phosphorylation. For behavioral assessment, cBARQ analysis showed improvement in stranger-directed fear, non-social fear, and trainability, while there were no differences in ADHD-like behavior and canine cognitive dysfunction (CCD) scores after 90 days of PB treatment. While only very minor shifts in bacterial taxonomy were detected, the higher SCFA concentrations after PB treatment could be one of the key differences between PB-R and PB-NR. These results suggest functional changes in GIM in canine IE treatment.
37

The application of food grade short chain fatty acids to prevent infestation of Tyrophagus putrescentiae on dry cured ham and the effects on sensory properties

Rogers, William D 01 May 2020 (has links)
Tyrophagus putrescentiae, (ham mite) is difficult for commercial dry cured ham producers to control. This research was conducted to test the efficacy of C8C9C10 fatty acids combined with and without food grade coatings to control mite infestations on dry cured hams. Ham cubes were coated directly or wrapped in nets saturated with combinations of xanthan gum (XG) or carrageenan (CG), propylene glycol alginate (PGA), and either propylene glycol or C8C9C10 fatty acid. The use of 10% C8C9C10 with XG and CG + PGA in direct coatings and 1% C8C9C10 with XG or 10% with both XG and CG/PGA in saturated nets inhibited mite population growth. Unexpectedly, the soybean oil solvent effectively controlled mite infestation. Sensory evaluation indicated that 10% C8C9C10 mixed with soybean oil and 100% soybean oil did not impart sensory differences to ham when used as a coating but did impact sensory attributes when used with nets.
38

Association of gut luminal metabolites and allergic responses

Fallata, Ghaith Mohammed January 2017 (has links)
No description available.
39

Role of Melatonin, Neuropeptide S and Short Chain Fatty Acids in Regulation of Duodenal Mucosal Barrier Function and Motility

Wan Saudi, Wan Salman January 2015 (has links)
The duodenal epithelium is regularly exposed to HCl, digestive enzymes, bacteria and toxins, and sometimes also to ethanol and drugs. The imbalance of aggressive factors in the intestinal lumen and mucosal barrier function increases the risk of tissue injury and inflammation. The key components of the duodenal barrier function include mucosal permeability, bicarbonate transport and the secretion or absorption of fluids. This thesis aims to elucidate the role of melatonin, neuropeptide S (NPS) and short chain fatty acids (SCFAs) in the regulation of intestinal mucosal barrier function and motility in the anesthetized rat in vivo and in tissues of human origin in vitro. Melatonin was found to reduce ethanol-induced increases in paracellular permeability and motility by a neural pathway within the enteric nervous system involving nicotinic receptors. In response to luminal exposure of ethanol, signs of mild mucosal edema and beginning of desquamation were observed in a few villi only, an effect that was not influenced by melatonin. Melatonin did not modify increases in paracellular permeability in response to luminal acid. NPS decreased basal and ethanol-induced increases in duodenal motility as well as bethanechol stimulated colonic motility in a dose-dependent manner. Furthermore, NPS was shown to inhibit basal duodenal bicarbonate secretion, stimulate mucosal fluid absorption and increase mucosal paracellular permeability. In response to luminal exposure of acid, NPS increased bicarbonate secretion and mucosal paracellular permeability. All effects induced by the administration of NPS were dependent on nitrergic pathways. In rats, administration of NPS increased the tissue protein levels of the inflammatory biomarkers IL-1β and CXCL1. Immunohistochemistry showed that NPS was localized at myenteric nerve cell bodies and fibers, while NPSR1 and nNOS were only confined to the myenteric nerve cell bodies. Perfusing the duodenal segment with the SCFAs acetate or propionate reduced the duodenal mucosal paracellular permeability, decreased transepithelial net fluid secretion and increased bicarbonate secretion. An i.v. infusion of SCFAs reduces mucosal paracellular permeability without any effects on mucosal net fluid flux. However, it significantly decreased bicarbonate secretion. Luminal SCFAs changed the duodenal motility pattern from fasting to feeding motility while i.v. SCFAs was without effect on motility. The systemic administration of glucagon-like peptide-2 (GLP-2) induced increases in mucosal bicarbonate secretion and fluid absorption. An i.v. GLP-2 infusion during a luminal perfusion of SCFAs significantly reduced the duodenal motility. In conclusion, the results in the present thesis show that melatonin, NPS and SCFAs influence the neurohumoral regulation of intestinal mucosal barrier function and motility. Aberrant signaling in response to melatonin, NPS and to luminal fatty acids might be involved in the symptom or the onset of disease related to intestinal dysfunction in humans. / <p>Research funders and strategic development areas:</p><p>- Bengt Ihre Foundation (grant SLS-177521)</p><p>- Socialstyrelsen(grant SLS-176671)</p><p>- Erik, Karin, and Gösta Selanders Foundation</p><p>- Emil and Ragna Börjesson Foundation</p><p>- Uppsala University </p><p>- Ministry of Education of Malaysia</p><p>- Universiti Malaysia Sabah, Malaysia</p>
40

Short and Long Chain Free Fatty Acids Differentially Regulate Glucagon-like Peptide-1 and Peptide YY Transcript Levels in Enteroendocrine Cells (STC-1)

Catherman, Colin M 01 January 2017 (has links)
The regulation of glucagon-like peptide-1 and peptide YY hormone levels are regulated based on different influential factors, but primarily levels are dependent upon ingested food content. As meals today become more fat-enriched, there is greater requirement for evaluation of these hormones that regulate insulin and satiety levels within the body. We have shown that the gene expression transcript production of glucagon-like peptide-1 and peptide YY are modulated by different concentrations, and times of short-chain fatty acids and long-chain fatty acids. Although the peptide hormone levels have the influential physiological role on effector tissue, the regulation of these hormones begins at the transcript levels. Recent research indicates that glucagon-like peptide-1 and peptide YY hormones are altered in response to different free-fatty acids. The present investigation generally demonstrated an overall decrease in both hormones after chronic exposure to fatty acids. Intestinal secretin tumor cell line (STC-1 cells) was used as a representative for intestinal L-cells. Quantitative real-time PCR analysis was used to determine the changes in RNA transcripts. Overall, there was a decrease in the 3-hour timeline, which continued to decrease in the 16-hour and 24-hour timelines for glucagon-like peptide-1. Peptide YY transcript expression in 3-hours increased significantly after exposure to propionate, a significant decrease after exposure to acetate, and no significant increase or decrease after exposure to butyrate. However, there was a significant decrease in peptide YY once reaching 24-hour exposure. It was determined there is a threshold for different concentrations of free-fatty acids to influence glucagon-like peptide-1 and peptide YY production, which was present in the different concentrations of butyrate. Lastly, exposure to both concentrations of linolenic acid caused a significant decrease in glucagon-like peptide-1 and peptide YY.

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