Dissertação (mestrado)—Universidade de Brasília, Brasília, Centro de Excelência em Turismo, 2015. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2015-11-18T20:09:28Z No. of bitstreams: 1 2015_NádiaLúciaAlmeidaNunes.pdf: 1419647 bytes, checksum: 97d288344ca273f5c36891a9d3a61b77 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2015-12-16T18:07:02Z (GMT) No. of bitstreams: 1 2015_NádiaLúciaAlmeidaNunes.pdf: 1419647 bytes, checksum: 97d288344ca273f5c36891a9d3a61b77 (MD5) / Made available in DSpace on 2015-12-16T18:07:02Z (GMT). No. of bitstreams: 1 2015_NádiaLúciaAlmeidaNunes.pdf: 1419647 bytes, checksum: 97d288344ca273f5c36891a9d3a61b77 (MD5) / Um dos desafios da oferta de alimentos e bebidas (A&B) para viajantes turistas é não somente garantir uma alimentação atrativa e gostosa, mas agregar qualidade de vida e saúde como benefícios, possibilitando aos turistas com restrição alimentar conforto e acesso seguro aos alimentos, característica do “bem receber” da hospitalidade. Contudo, a incerteza de ser atendido em suas necessidades alimentares pode gerar insegurança e desmotivar o turista, já que algumas pessoas, quando em viagem, tornam-se mais vulneráveis em relação à alimentação, uma vez que nem sempre o que está disponível permite opção de escolha dentro das suas necessidades e restrições, podendo trazer sérios danos à saúde em decorrência da mudança na rotina alimentar. A prática da hospitalidade em turismo pode agregar maior qualidade ao setor de alimentos e bebidas, contribuindo para a redução dos efeitos de uma inospitalidade quase sempre danosa para o público com necessidades especiais durante suas viagens. Este estudo objetiva contribuir para a compreensão acerca da relação existente entre a hospitalidade, turismo e oferta de A&B, adotando como ponto de reflexão a regulamentação (politicas públicas) existente e a necessidade de qualificação profissional para atendimento do público com as restrições alimentares. A construção deste estudo foi partir de referências coletadas em pesquisa bibliográfica sobre a complexidade que envolve os temas centrais. Em seguida, através de uma breve pesquisa documental, sobre a oferta de A&B, nos desjejuns dos meios de hospedagem de Brasília, para o publico com as restrições alimentares: Doença Celíaca e Intolerância a Lactose. Os resultados revelam que a maioria dos hotéis analisados oferece em seu desjejum algum alimento que possa ser consumido pelas pessoas com restrições alimentares abordadas nessa pesquisa. Contudo, a maioria dos hotéis desconhece essa informação e desta forma não pode assegurar que haja oferta, impossibilitando também a divulgação deste serviço diferenciado. Como resultado da reflexão, espera-se que os setores turismo/alimentação/hotelaria possam colocar em prática as políticas públicas existentes e propor a criação de novas, já que se percebe a necessidade de um olhar atento ao publico com restrição alimentar, onde nota-se falha na qualificação profissional destas áreas. Portanto, existe a necessidade da oferta de um serviço hospitaleiro que garanta segurança e conforto ao publico com restrição alimentar. ______________________________________________________________________________________________ ABSTRACT / One challenge of food and beverages (F&B) offer for tourist travelers is not only ensure attractive and tasty food, but add quality of life and health as benefits, enabling comfort and secure access to food for tourists with food restriction, the “welcoming” hospitality characteristic. However, the uncertainty of being attended to their dietary requirements can cause insecurity and discouraging tourists, since some people become more vulnerable in relation to food when traveling, because what's available not always allows the tourist to make a choice between the options according to its needs and restrictions, causing serious health problems due to eating routine changes. The practice of tourism hospitality can add more quality to food and beverages (F&B) sector, helping in reducing the effects of inhospitality almost always harmful to people with special needs during their travels. This study aims to contribute for the comprehension adopting as a point of reflection the existing regulation (public policies) and the need of professional qualification for customer service, focusing on people with food restrictions. The construction of this study started from references found in bibliographic research about the complexity that involves those central themes. Then, through a brief documentary research, about food and beverages (F&B) offered in breakfasts provided by lodging facilities in Brasilia (Brazilian Capital), to people with food restriction as Celiac Disease and Lactose Intolerance. The results showed that most of the hotels analyzed offer some products at breakfast that can be consumed by people with food restrictions approached in this research. Although, most of the hotels didn‟t know this information, meaning that they can‟t ensure the offer, also disallowing the divulgation of this differentiated service. As a result of the reflection, it is expected that tourism/food/hospitality sectors can put into practice the existing public policies and propose the creation of new ones, since there is a need of a cautious look at people with food restrictions because it can be noticed that there is a flaw in professional qualification of those areas (tourism/food/hospitality). Therefore, there is a need of the offer of hospitable service that ensures safety and comfort to the public with food restriction.

Master of Science / Food Science Institute / Fadi Aramouni / Flour from the fruit of breadfruit trees (Artocarpus altilis) holds the potential to serve as an alternative to gluten-containing flour and may aid in alleviating food insecurity. This study assessed the effects breadfruit flour contributes to gluten-free bread quality. Breadfruit flour was included at a baker’s percentage (0, 20, 35, 50%) of a gluten-free flour blend, and was treated with various leavening agents (yeast, 15% baking powder, 20% baking powder) to create varying gluten-free bread formulas. Density and pH of each batter was assessed along with loaf density, yield, specific volume, pH, water activity, crust color (L*, a*, b*), crumb color (L*, a*, b*), and texture. Additionally, a consumer sensory study was performed to ascertain degree of liking of appearance, color, flavor, texture, aftertaste, likelihood to purchase, and overall acceptability. Significant differences (p < 0.05) were found in batter pH, loaf density, yield, specific volume, color (crust b*, crumb L*, a*, b*), pH, water activity, and texture among flour inclusion and leavening treatments. Consumer testing yielded significant differences (p < 0.05) between the control and a yeast leavened 20% breadfruit formula in appearance, color, flavor, aftertaste, likelihood to purchase, and overall acceptability. While most consumers rated the breadfruit treatment lower than the control, five celiac panelists rated it higher. Among all treatments, loaves produced from 20% breadfruit flour inclusion had significantly lower density, yield, hardness, adhesiveness, gumminess, chewiness, and crumb yellowness (b*), as well as higher specific volume, springiness, crust yellowness (b*) and darkness (L*), crumb darkness (L*), and magenta hue (a*) compared to other breadfruit flour inclusion levels. Similarly, loaves leavened with yeast had significantly lower batter pH, loaf pH, density, yield, hardness, chewiness, crust yellowness (a*), crumb darkness (L*), magenta hue (a*), and yellowness (b*) as well as higher loaf water activity, volume, springiness, and crust darkness (L*) compared to other breadfruit flour inclusion levels. These results indicate breadfruit flour can be used at ≤ 20% in gluten-free bread formulas to replace rice flour and has potential as a fiber supplement. Further research is needed to assess how breadfruit flour affects the quality of other gluten-free product formulas.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, 2006. / Submitted by Alexandre Marinho Pimenta (alexmpsin@hotmail.com) on 2009-10-09T15:51:54Z No. of bitstreams: 1 2006_Míriam Pereira Soares.pdf: 393749 bytes, checksum: a3ddda0542e95bef0aedb969aa1d97bc (MD5) / Approved for entry into archive by Luanna Maia(luanna@bce.unb.br) on 2009-10-23T15:05:10Z (GMT) No. of bitstreams: 1 2006_Míriam Pereira Soares.pdf: 393749 bytes, checksum: a3ddda0542e95bef0aedb969aa1d97bc (MD5) / Made available in DSpace on 2009-10-23T15:05:10Z (GMT). No. of bitstreams: 1 2006_Míriam Pereira Soares.pdf: 393749 bytes, checksum: a3ddda0542e95bef0aedb969aa1d97bc (MD5) Previous issue date: 2006 / Introdução: A doença celíaca (DC) ou enteropatia sensível ao glúten é uma afecção inflamatória de variável severidade que ocorre tanto em crianças como em adultos, sendo caracterizada por intolerância permanente a proteínas contidas no glúten do trigo e em cereais afins, principalmente a cevada e o centeio. Estudos realizados para diagnóstico da doença celíaca têm demonstrado que ela não é tão rara no Brasil. Objetivo: determinar a prevalência da doença celíaca em grupo de usuários atendidos em cinco postos de saúde do município de Dourados (MS). Material e métodos: Foram colhidas 1105 amostras de sangue de usuários da rede básica de saúde do município de Dourados – MS com idade superior a um ano para teste com anticorpos antitransglutaminase (IgA-tTG) e antiendomísio (IgA-EmA). Resultados: a prevalência encontrada foi de 1:1105, demonstrando resultado mais baixo do que a prevalência encontrada em estudo anterior. Conclusão: O resultado foi provavelmente devido ao número insuficiente de indivíduos pesquisados. O único paciente positivo para DC não apresentava os sintomas clássicos, demonstrando assim a importância de rastreamento na população em geral. ______________________________________________________________________________________ ABSTRACT / Introduction: Celiac Disease (CD) is an inflammatory intestinal disorder of changeable severity that occurs in such a way in children as in adults, being characterized by permanent intolerance proteins contained in gluten of the wheat and similar cereals, mainly the barley and the rye. Studies carried through for diagnosis of the CD have demonstrated that it is not so rare in Brazil. Objective: to determine the prevalence of the CD in users of five health units centers in Dourados (MS). Material and methods: 1105 users blood samples had been investigated with antitransglutaminase (IgA-tTG) and antiendomisium antibodies (IgA-EmA). Results: the CD frequency was 1:1105, demonstrating prevalence below the expected one. Conclusion: this result was probably due to the insufficient number of participants. The only positive patient for CD did not present the classic symptoms, thus demonstrating the importance of serological screening in the population in general.

Durante o processamento industrial de produtos alimentícios, tendem a ocorrer modificações físicas e/ou químicas nos diferentes componentes, que interferem diretamente em seus atributos típicos. Portanto, torna-se necessária a avaliação do comportamento físico-químico de cada componente, bem como de suas misturas. Dois tipos de proteína, proteína isolada de soja e glúten, tiveram suas propriedades morfológicas, térmicas e reológicas avaliadas neste trabalho. Estas propriedades também foram investigadas para os amidos de trigo, mandioca e milho, incluindo-se a determinação de amido danificado e o acompanhamento do processo de gelatinização através da microscopia óptica utilizando luz polarizada. Para investigar o efeito individual dos componentes, foram aplicados vários planejamentos experimentais de misturas do tipo simplex contendo diferentes concentrações de proteína isolada de soja/glúten/amido. A influência da fonte botânica do amido também foi verificada. Parâmetros reológicos como força de ruptura, dureza, deformabilidade, fluidez e força de penetração foram determinados para géis obtidos a partir das misturas preparadas, permitindo assim um estudo comparativo. Através da quimiometria, modelos de ajuste lineares, quadráticos e cúbicos foram aplicados para obter equações polinomiais que pudessem expressar adequadamente as superfícies de resposta observadas para cada parâmetro reológico avaliado. A significância estatística desses modelos foi avaliada através da análise de variância e de um novo ensaio experimental, sendo possível indicar o melhor modelo de ajuste para cada propriedade reológica estudada. / Physical and/or chemical modifications that happen in the ingredients during industrial process of food products interfere directly in their typical attributes. Therefore, the physical-chemistry behavior evaluation of each ingredient and their blends make necessary. Two kinds of proteins, isolate soy protein and gluten, have been their morphological, thermal and rheological properties evaluated in this work. These properties have been investigated to wheat, corn and tapioca starches, damaged starch determination and gelatinization process following using light microscopy with polarized light were included. In order to investigate the effects of the individual components, applied several mixture simplex design for modeling experiments of blends with different isolate soy protein/gluten/starch ratios. The influence of botanical source of starch was also investigated. Rheological parameters like rupture strength, hardness, deformability, firmness and penetration strength of the gels obtained through the prepared blends were determined make possible a comparative study. Using chemometry, linear, quadratic and special cubic models were studied to get polynomial equations that express the observed surface response to each evaluated rheological parameter. The statistical significance of these models was obtained using analysis of variance and new experimental blend, being possible indicate the better model to each studied rheological parameter.

Master of Science / Department of Grain Science and Industry / Rebecca A. Regan / Sorghum is unique in terms of its resistance to drought and heat and is grown and consumed around the globe. Moreover, sorghum does not contain gluten and has potential in the gluten-free market. A blend of non-wheat flour, starch and hydrocolloid typically provide the structure of gluten-free products. Most research on sorghum bread uses a yeast leavened process, HPMC gum, rice flour and corn, potato, or tapioca starch. Little is known about the functionality or interactions of different starches and hydrocolloids in sorghum batter. The objectives of this study were to examine starch-hydrocolloid interaction in chemically leavened gluten free sorghum bread; to evaluate the effects of different ingredients on gluten free bread quality made with sorghum flour: starch (tapioca starch, rice flour and potato starch): hydrocolloid (HPMC, locust bean gum and xanthan) and to develop a chemically leavened gluten free sorghum bread method. Bread was baked as pup loaves. Volume index was measured using the AACCI Method 10-91.01 template, crumb grain was evaluated using the C-Cell Imaging System and texture was determined with the TA.XT Plus Texture Analyzer. The base formula was commercial sorghum flour, water, starch, hydrocolloid, sugar, salt, shortening and double acting baking powder. Sorghum flour: starch (tapioca starch, rice flour and potato starch) ratios of 70:30, 80:20 and 90:10 were tested. Loaves containing all levels of rice flour had the same volume index (~165) as 100% sorghum flour (168) while all levels of tapioca starch and potato starch produced significantly smaller loaves (~150). The ratio of 90% sorghum flour and 10% starch (tapioca starch, rice flour and potato starch) was selected. The type and level of hydrocolloid significantly impacted loaf volume, grain and texture. Starch-hydrocolloid combinations which produced the best loaves were tapioca starch + 3% HPMC, rice flour + 3% xanthan and potato starch + 4% xanthan. Following initial optimization experiment, egg ingredients, fat, baking powder and water were added and evaluated individually to develop an optimized formulation. In general, addition of egg ingredients, shortening and oil did not improve the overall quality of sorghum based bread and were not added to the formula. However, emulsified shortening was effective. The best level of emulsified shortening was determined to be 3% for the breads with sorghum flour: tapioca starch or sorghum flour: potato starch and 5% for bread made with sorghum flour: rice flour. The best baking powder (SALP and MCP) levels were 5, 8 and 5% for sorghum flour: tapioca starch bread, sorghum flour: rice flour bread and sorghum flour: potato starch bread, respectively. Optimum levels of water for sorghum flour: tapioca starch bread, sorghum flour: rice flour bread, and sorghum flour: potato starch bread were 120, 110 and 120%, respectively. This research showed that different starch sources have different interactions with other ingredients in chemically leavened sorghum based gluten free bread.

The benefits of fortification of poor quality food proteins such as wheat gluten with limiting amino acids depend on the biological availability of the added amino acids and their stability with respect to processing and storage. Although simple addition of amino acids in free form is convenient, the potential improvement in nutritional quality by this method of fortification may not materialize due to possible losses during processing steps such as washing, susceptibility to degradative reactions, and different rates of absorption and utilization compared to protein-bound amino acids. In this study, covalent attachment of lysine and threonine to wheat gluten was investigated using the chemical carbodiimide reaction and the enzymatic plastein reaction. The nutritional quality of enriched products was evaluated by in vitro and microbiological tests, and susceptibility to destruction by heating in the presence of a reducing sugar was investigated. Covalent attachment of lysine ethyl ester or threonine to gluten by the plastein reaction utilizing the enzyme papain was not successful. Although lysine and threonine contents in the products were increased, these results were attributed to selective enzymatic release of other amino acids. The amino acid compositions of undialyzable "plastein" products were markedly different from the original gluten substrate, and product yields were low. The results suggest the formation of many dialyzable peptides and free amino acids, and inability for protein re-synthesis from these low molecular weight compounds. Covalent lysine and threonine contents were increased using the carbodiimide reaction. In general, the reaction was most influenced by pH, reactant concentration and type of reactant. Products enriched via primarily peptide bonds as well as products enriched via peptide and isopeptide bonds could be prepared using various starting materials. Lysine, N -acetyl lysine, N -benzylidene lysine and threonine were coupled through amide bond formation to gluten, sodium stearate-solubilized gluten, acid-solubilized gluten or pepsin-solubilized gluten. Sodium stearate solubilization did not improve extent of amino acid incorporation. Pepsin hydrolysis of gluten enhanced amino acid attachment but decreased product yields. 4.0-fold and 6.5-fold increases in lysine content resulted by reaction of pepsin-solubilized gluten with N e-benzylidene lysine and N-acetyl lysine, respectively. However, yields of these products were low (47% and 58%). 1.6-fold, 2.0-fold and 2.5-fold increases were obtained by reaction of gluten with Ne-benzylidene lysine, lysine and N£-acetyl lysine, respectively, with product yields of 90 to 95%. At least 20-fold and 5-fold increases could be achieved by reaction of 0.5N HCI and 0.05N HCI solubilized glutens respectively with lysine, with product yields of 80 to 90%. 4-fold and 2-fold increases in threonine content resulted from reaction of threonine with pepsin-solubilized gluten and gluten, respectively. Simultaneous attachment of lysine or lysine derivative and threonine was not effective. In vitro evaluation of availability and digestibility of covalently enriched products was carried out by the DNBS reaction and pepsin pancreatin digestion tests. The results indicate the formation of isopeptide bonds involving the £-amino group of lysine unless N -substituents of lysine were used. Isopeptide bonds involving the Y_carboxyl groups were indicated when gluten had been solubilized by acid treatment. Peptide bond formation predominated when N -benzylidene or N -acetyl lysine was attached to pepsin-solubilized gluten or gluten. The high hi vitro availability and digestibility values for N £-benzylidene lysine enriched products suggest lability of the Schiff's base linkage of this N £-substituent, in contrast to the stability of the amide linkage in Ne -acetyl lysine. Microbiological evaluation by a Tetrahymena bioassay confirmed the nutritional improvement of gluten by covalent attachment of lysine, Ne-acetyl lysine or Ne-benzylidene lysine. Relative nutritive value of gluten was 54, whereas covalently and freely enriched glutens had relative nutritive values similar to that of the reference casein, assigned a value of 100. Covalently and freely lysine enriched glutens were compared for color and extent of lysine destruction after baking. In general, covalently enriched products had lighter color and higher percentages of total, DNBS-available and pepsin-pancreatin-digestible lysine contents than freely enriched products. N e-Benzylidene lysine enriched gluten was particularly stable, with relative nutritive value of 88 compared to 44 for baked gluten. It is concluded that covalently attached lysine is more stable than free lysine for enrichment of food proteins susceptible to Maillard reaction. / Land and Food Systems, Faculty of / Graduate

La creciente demanda de productos libres de gluten ha favorecido el desarrollo de numerosos productos de panadería buscando imitar las características de calidad de sus homólogos elaborados con trigo. Sin embargo, en dichos desarrollos ha primado la calidad tecnológica y se han obviado otros aspectos como el nutricional. El objetivo de este estudio ha sido el diseño científico de productos horneados sin gluten (panes y magdalenas) elaborados utilizando harina de arroz, integrando aspectos tecnológicos, sensoriales y nutricionales. El estudio incluyó la evaluación de panes libres de gluten de origen comercial y el diseño de nuevas formulaciones sobre las cuales establecer correlaciones entre las propiedades de las masas y los parámetros tecnológicos de los productos horneados. En el diseño de magdalenas se puso especial énfasis a la evaluación del rol de las proteínas sobre las propiedades reológicas de las masas formuladas y las características tecnológicas del producto final. Los panes sin gluten comerciales mostraron un perfil nutricional muy variable, en general con un bajo contenido en proteína y alto en grasa. Los productos formulados, tanto panes como magdalenas sin gluten presentaron un buen contenido de proteínas y gran variabilidad en las características tecnológicas. El análisis reológico de las masas libres de gluten y los parámetros tecnológicos y sensoriales de los productos horneados resultantes permitieron establecer correlaciones positivas entre las propiedades de hidratación de la miga y algunos parámetros de textura, y entre la dureza-TPA y los parámetros reológicos de las masas caracterizadas mediante el Mixolab, los cuales podrían utilizarse como predictores de la calidad para los panes libres de gluten. El estudio reológico de las mezclas formuladas para elaborar magdalenas a base de harina de arroz demostró que las propiedades reológicas de las masasbatidas estuvieron gobernadas por el tipo de proteína utilizada en cada formulación. En general, la presencia de clara de huevo confiere propiedades viscoelasticas a la masa-batida basada en harina arroz que permitierón obtener magdalenas con mejores características tecnológicas. / Matos Segura, ME. (2013). Formulación y desarrollo de productos horneados libres de gluten a base de harina de arroz enriquecidos con proteínas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/28273 / TESIS

The only treatment for celiac disease (CeD), an autoimmune disorder triggered by the ingestion of gluten, is lifelong adherence to a gluten-free diet (GFD). CeD and the GFD have been shown to be associated with low quality of life (QoL). In some individuals, such a strict diet can lead to disordered eating attitudes and behaviors. The purpose of this study was to better understand the extent to which disordered eating attitudes and behaviors may be common in a sample of adults diagnosed with CeD, as well as the relationship with various factors and QoL measures, including anxiety and depression. The study is a cross sectional pilot study of 50 individuals with CeD. Patients between the ages of 18 to 45 years old (mean=29.56, SD=7.40) with a biopsy-proven CeD diagnosis, following a GFD for at least a year (mean=7.20, SD=5.31) with no previous or current eating disorder diagnosis were recruited. In this study, suggestive ED (based on EDDS) and DE (based on EPSI) were present, but low (2% suggestive diagnosis of BED, 12% suggestive diagnosis of OSFED as per DSM-V). The distribution of the self-reported food attitudes and behaviors measures (CD-FAB scores) were spread out around the mean 36.96 (15.30) with a maximum score of 66 out of a possible 77. The CD-FAB may have utility in identifying adults with CeD that may be at risk for disordered eating attitudes and behaviors, particularly those in the first few years after diagnosis. It likely has limited utility in identifying suggestive EDs (as per EDDS) and DE (as per EPSI). The main factors that were associated with higher CD-FAB scores were BMI, number of symptoms, years since diagnosis, diet adherence and personality characteristics. Seven years after diagnosis seems to be an important cut-point in how participants rated food attitudes, fear responses and adaptive responses on the CDFAB scales. Higher CD-FAB scores had a significant and meaningful association with QoL scores. Participants recruited during the COVID-19 pandemic had significantly lower CD-FAB scores and higher QoL scores compared to those recruited pre-pandemic; despite not having significant differences in any other demographic characteristics.

Tesis por compendio / [EN] Celiac disease (CD) is a chronic enteropathy triggered by cereal gluten proteins in genetically predisposed individuals. The etiology is strongly associated with the genes of the human leukocyte antigen (HLA) encoding the DQ2/DQ8 molecules. Most CD patients carry this genotype but this is also present in the 40% of the general population and only a small percentage develops the disease. Thus, the HLA-DQ genotype is necessary but not solely responsible for the disease development. Gluten is the main environmental trigger but its intake neither fully explains the onset nor its clinical manifestations. Other environmental factors (e.g. early feeding practices, infections, intestinal microbiota) have been associated with the risk of developing CD. The only treatment for CD patients is the adherence to a gluten free diet (GFD), but the compliance with this dietary strategy is complicated because gluten is present in many foods. Therefore, the identification of modifiable environmental factors that contribute to CD onset is critical for the development of strategies to reduce its incidence. Observational studies in CD patients revealed imbalances in the intestinal microbiota which could contribute to the pathogenesis of the disease. It has been proposed that these imbalances are not only a secondary consequence of the disease but could also be a predisposing factor. To understand whether gut microbiota imbalances play a role in CD onset and pathogenesis, in vitro, animal and human prospective and intervention studies have been conducted in the context of the present PhD Thesis. The global aim of this Thesis has been to improve the understanding of the role played by intestinal microbiota in the pathogenesis and risk of CD, and the possibilities of contributing to disease prevention and treatment by modulating gut microbiota composition. Chapter 1 includes two in vitro studies investigating the influence of components of the gut microbiota (bifidobacteria and enterobacteria) on the maturation and functions of immunocompetent cells (dendritic cells), and on gluten toxicity in the intestinal epithelium (Caco-2 cells). We have observed that some Bifidobacterium strains are able to reduce the activation of dendritic cells and ameliorate the toxicity of gluten on intestinal epithelial cells. In Chapter 2 the effects of the administration of Bifidobacterium longum CECT 7347 was evaluated in an in vivo model of gluten induced enteropathy in newborn rats, resulting in a reduced proinflammatory cytokine production in the small intestine and CD4+T cell numbers in peripheral blood. Chapter 3 includes two observational studies in humans to unravel whether breast-feeding and human milk composition and/or the host genotype (HLA-DQ) are related to the microbiota, thereby influencing the later development of CD. We concluded that both factors may contribute to the early intestinal colonization of the infant's gut, influencing the Bifidobacterium spp. numbers. Human milk composition also varies in CD and non-CD mothers, modifying the supply of bifidobacteria and protective immune factors to the offspring. Finally, in Chapter 4 we have studied the potential beneficial effects of the administration of B. longum CECT 7347 in addition to the GFD to children with newly diagnosed CD. This study demonstrates that the bifidobacteria slightly reduces serum inflammatory markers and restored the gut microbiota composition. / [ES] La enfermedad celíaca (EC) es una enteropatía crónica de carácter autoinmune que sufren individuos genéticamente predispuestos tras la ingesta de gluten. La etiología está asociada con los genes del sistema "Antígeno Leucocitario Humano" (HLA) que codifican las moléculas DQ2/DQ8. Los pacientes con EC presentan este genotipo, sin embargo este también está presente en ¿40% de la población general y sólo un pequeño porcentaje desarrolla la enfermedad. Por lo tanto, el genotipo HLA-DQ resulta necesario pero no suficiente para que se desarrolle la enfermedad. El gluten es el principal desencadenante pero su ingesta tampoco explica su desarrollo ni sus manifestaciones clínicas. Otros factores ambientales (p.e. la lactancia, infecciones, microbiota intestinal) se han asociado con el riesgo de desarrollar la EC. El único tratamiento para los pacientes celíacos es el seguimiento de una dieta exenta de gluten (DEG), sin embargo su cumplimiento es complicado debido a que el gluten está presente en la mayoría de los alimentos procesados. Por ello, la identificación de factores ambientales modificables que contribuyan al desarrollo de la enfermedad, resulta fundamental para desarrollar estrategias que permitan reducir su incidencia. Estudios observacionales realizados en pacientes con la EC, han demostrado la existencia de desequilibrios en su microbiota intestinal, que podrían contribuir a la patogénesis de la enfermedad. Se ha propuesto que estos desequilibrios no son sólo una consecuencia secundaria de la EC, sino que podrían ser un factor predisponente. Para entender si la microbiota está implicada en el desarrollo y patogénesis de la EC, en la presente Tesis se han desarrollado estudios in vitro, con animales y estudios prospectivos y de intervención en humanos. El objetivo de esta Tesis ha sido avanzar en el conocimiento de la función que la microbiota intestinal desempeña en la patogénesis de la EC, así como, acerca de las posibilidades de tratar o prevenir esta enfermedad mediante la modulación de la composición de la microbiota intestinal. El Capítulo 1 incluye dos estudios in vitro en los que se ha estudiado la influencia de componentes de la microbiota intestinal (bifidobacterias y enterobacterias) en la maduración y las funciones de células inmunocompetentes (células dendríticas), y en la toxicidad del gluten en el epitelio intestinal (células Caco-2). Hemos observado que algunas cepas de Bifidobacterium son capaces de reducir la activación de las células dendríticas y de reducir la toxicidad del gluten sobre el epitelio intestinal. En Capítulo 2 incluye el estudio de los efectos de la administración de B. longum CECT 7347 en un modelo de enteropatía inducida por gluten en ratas recién nacidas, observándose una reducción de citoquinas proinflamatorias en el intestino y de células T CD4+ en sangre periférica. El Capítulo 3 incluye dos estudios observaciones en humanos en los que se ha investigado si la lactancia y composición de la leche materna y/o el genotipo (HLA-DQ) están relacionados con la microbiota y, si así, podrían influir en el desarrollo de la EC. Concluimos que ambos factores contribuyen a la colonización intestinal del niño en los primeros meses de vida, afectando especialmente al número de Bifidobacterium spp. La composición de la leche maternal varía entre madres celíacas y sanas, lo que podría modificar el aporte de bifidobacterias y factores inmunológicos protectores al lactante. Por último, en el Capítulo 4 incluye el estudio del potencial efecto beneficioso de la administración de B. longum CECT 7347 junto con la DEG en niños recién diagnosticados de EC. Este estudio demuestra que la bifidobacteria ligeramente reduce los marcadores inflamatorios en sangre periférica y contribuye a restablecer la composición de la microbiota intestinal. / [CA] La malaltia celíaca (MC) és una enteropatia crònica provocada per les proteines del gluten de cereals en individus predisposats genèticament. L'etiologia està fortament associat amb els gens de l'antigen leucocitari humà (HLA). Pacients amb MC porten aquest genotip però també està present en aproximadament el 40% de la població general i només un petit percentatge (1-3%) es desenvolupa la malaltia. Per tant, HLA-DQ genotip és necessària, però no l'únic responsable. El gluten és el principal desencadenant ambiental però la seva ingesta no explica completament l'inici ni les seves manifestacions clíniques. Altres factors ambientals, com la microbiota intestinal, s'han associat amb el risc de desenvolupar CD. Els estudis observacionals en pacients amb MC van revelar desequilibris en la microbiota intestinal que podria contribuir a la patogènesi de la malaltia. S'ha proposat que aquests desequilibris no només són una conseqüència secundària de la malaltia, però també podria ser un factor predisponent. Per entendre si els desequilibris microbiota intestinal podrien tenir un paper en l'aparició de CD, un estudi prospectiu amb el nen en risc la família està en marxa. L'únic tractament per als pacients amb EC és l'adherència a una dieta lliure de gluten, però el seu compliment és complicada a causa del gluten està present en molts aliments. La identificació de factors ambientals modificables que contribueixen a l'aparició de CD és fonamental per a les estratègies de desenvolupament que porten a una reducció de la incidència. Aquest pot ser el cas per als components de la microbiota intestinal, l'adquisició podria ser modulada per factors ambientals i dietètics. L'objectiu global de la tesi és desentranyar els coneixements actuals sobre el paper exercit per la microbiota intestinal en la patogènesi de l'EC, i les possibilitats de contribuir a la prevenció i tractament de la malaltia mitjançant la modulació de la composició de la microbiota intestinal En el Capítol 1 hem estudiat l'ús de models in vitro de la influència de la microbiota intestinal durant la maduració i funcions del sistema immunològic (cèl·lules dendrítiques), i les interaccions entre el gluten i intestinal intestí i la resposta de l'epiteli intestinal resultant d'aquesta interacció. Hem observat que alguns ceps de Bifidobacterium són capaços de reduir l'activació del sistema immune i millorar la resposta nociva de l'epiteli intestinal a l'estimulació amb gluten. En el Capítol 2 hem estudiat els efectes de l'administració d'una soca de Bifidobacterium (B. longum CECT 7347) per a un model animal de rates nounades. El tractament amb els bacteris es va associar amb una reducció en la producció de citocines proinflamatòries i la resposta immune de cèl·lules T CD4 +. En el Capítol 3 es va descriure que alguns genètic (HLA-DQ genotip) i factors ambientals (llet materna) influeixen en la colonització intestinal primerenca, especialment en Bifidobacterium spp., que poden influir en l'aparició de CD més tard. Finalment, en el Capítol 4 s'ha estudiat l'efecte probiòtic de l'administració de B. longum CECT 7347 en nens acabats diagnosticats d'EC i el seu paper en el restabliment de la salut intestinal. / Olivares Sevilla, M. (2015). Influence of intestinal microbiota in celiac disease pathogenesis and risk [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58768 / TESIS / Premios Extraordinarios de tesis doctorales / Compendio

This study is a netnography of an online gluten-free community through the scope of the Facebook group "Gluten Free." The objective of this qualitative inquiry is to investigate the key characteristics of this online gluten-free community and gain a deeper understanding of member purposes for participation. Employing the method of netnography allows for an unobtrusive exploration of the community by discreetly utilizing anthropological techniques in an online setting. Despite growing awareness, no academic research has yet been conducted on the social aspects of the online gluten-free community. The thematic findings that emerged from this study were two-fold. First, this investigation revealed three key characteristic themes in the content of community posts: suspiciousness and distrust, defensiveness and frustration, and passion and determination. Second, this analysis discovered three purposive themes for member participation: validation, friendship, and education. The findings of this study render a thick description of the unique culture of the online gluten-free community, sharpen the academic understanding of online communities, and strengthen the valuable method of netnography.