Submitted by MAYARA CORRÊA PEIXOTO null (mayarapeixoto@gmail.com) on 2016-01-21T19:10:56Z No. of bitstreams: 1 DISSERTAÇÃO DEFINITIVO.pdf: 2637809 bytes, checksum: 171595b1d99f68cdfbe44623d1901fda (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-25T13:08:24Z (GMT) No. of bitstreams: 1 peixoto_mc_me_jabo.pdf: 2637809 bytes, checksum: 171595b1d99f68cdfbe44623d1901fda (MD5) / Made available in DSpace on 2016-01-25T13:08:24Z (GMT). No. of bitstreams: 1 peixoto_mc_me_jabo.pdf: 2637809 bytes, checksum: 171595b1d99f68cdfbe44623d1901fda (MD5) Previous issue date: 2015-12-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O aumento da expectativa de vida dos animais de companhia tem estimulado as pesquisas em nutrição para cães e gatos seguir a tendência da nutrição humana, que visa estudar intervenções que proporcionem melhor qualidade de vida e favoreçam a saúde como um todo, retardando ou até mesmo minimizando o aparecimento de doenças relacionadas ao envelhecimento. Cães idosos apresentam inflamação de baixo grau na mucosa do trato gastrointestinal, evidenciada por enterites e colites discretas a moderadas. O consumo de dieta contendo carboidratos fermentáveis, como o amido resistente (AR) pode amenizar essas alterações provocadas pela idade. O fornecimento de substrato fermentável para a microbiota intestinal, com correspondente produção de ácidos graxos de cadeia curta, em especial o butirato favorece melhor suporte nutricional à mucosa, influenciando sua estrutura e função, com potenciais benefícios à saúde e diminuição de inflamação. Este estudo avaliou os efeitos do consumo de amido resistente (AR) em cães idosos sobre a digestibilidade dos nutrientes, produtos de fermentação, IgA fecal e as características histológicas da mucosa intestinal. Uma mesma formulação foi processada de dois modos diferentes, originando ração com baixo (0,21%) e elevado (1,46%) teor de AR. Os resultados de consumo, digestibilidade, produtos de fermentação e IgA foram avaliados pela função GLM do SAS, considerando esquema fatorial 2x2, com dois tempos e dois tratamentos. Os dados de morfometria das criptas do intestino grosso foram analisados pelo teste T-pareado. Os resultados histológicos das biopsias intestinais foram avaliados por estatística não paramétrica, utilizando-se o teste de Wilcoxon para dados pareados (P<0,05). A digestibilidade da proteína (P=0,002) e do extrato etéreo (<0,001) foi maior na dieta com menos AR. Quando alimentados com a ração com mais AR, as fezes dos cães apresentaram menor pH, maiores teores de propionato, butirato, ácidos graxos voláteis totais e lactato (P<0,05). À análise histológica, não foi verificado diferença significativa em nenhum parâmetro analisado quando comparado os valores obtidos no período final de consumo da ração baixo AR e elevado AR. À análise morfométrica, foi observada tendência ao aumento do tamanho das criptas do cólon descendente dos cães que consumiram a ração com elevado AR (P=0,083). No presente estudo, mesmo apresentando efeitos sobre os produtos de fermentação bacterianos e pH fecal, não houve alterações benéficas significativas na mucosa gastrointestinal, que demonstram ser necessários mais estudos sobre o assunto em cães. / The increase in life expectancy of pets has stimulated researchs in dogs and cats nutrition that follow the tendency of human nutrition ones, aim and to study interventions that can improve quality of life and promote health, slowing or even minimizing the onset of diseases related to the aging process. Elderly dogs present low degree of inflammation in the mucosa of the gastrointestinal tract, evidenced by discrete to moderate enteritis and colitis. The consumption of diet containing fermentable carbohydrates such as resistant starch (RS) can reduce these changes caused by age. The supply of fermentable substrate for the intestinal microbiota, stimulates short chain fatty acids production, specially butyrate, that favors a better nutritional support to the mucosa influencing its structure and function with potential health benefits and reduction of inflammation. This study evaluated the effects of resistant starch (RS) consumption on nutrient digestibility, fecal concentration of fermentation products, histologic and morphometric characteristics of the intestinal mucosa of elderly dogs. A basal diet was processed in two different extrusion conditions to obtain two treatments: diet with low (0.21%) and high (1.46%) RS content. Feed intake, nutrient digestibility, fermentation products and fecal IgA were performed by GLM procedure of SAS considering a 2x2 factorial arrangement of treatments, two times and two treatments. Morphometric characteristics from large intestine were evaluated by T-paired test. Histological evaluation of intestinal biopsy were assessed by non-parametric statistic using Wilcoxon test for paired data (P<0.05). Protein (P=0.002) and fat (P<0.001) digestibility were higher for diet with low RS. Dogs receiving high-RS diet had lower fecal pH and higher concentration of values for propionate, butyrate, total volatile fatty acid and lactate (P<0.05). There was no significant differences in either parameter analyzed the histological analysis compared the values obtained in the final period feed consumption of low and high AR. According to the morphometric evaluation there was increase in the crypt size in descending colon of dogs receiving high-RS diet (P=0.083). Even with effects on bacteria fermentation products and fecal pH, there were no significant beneficial changes on gastrointestinal mucosa, that suggests that more studies on this issue are required.

Dans l'alimentation des pays industrialisés, l'apport en protéines est bien supérieur à l'apport nutritionnel conseillé (ANC). De plus, cet apport peut être encore supérieur lors de la consommation de régimes riches en protéines utilisés à des fins de perte de poids par des personnes obèses ou en surpoids. Cependant, les conséquences des régimes riches en protéines au niveau de l'écosystème du gros intestin sont encore très mal connues. Dans la première partie de cette thèse, nous avons étudié l'impact d'un régime hyperprotéique sur le microbiote, le contenu endoluminal du gros intestin et le métabolisme des colonocytes. Les rats ont consommé pendant 15 jours soit un régime hyperprotéique (53% de protéines) soit un régime normoprotéique (14% de protéines). Nous avons observé que le régime hyperprotéique réduit la quantité des groupes bactériens majeurs comme Clostridium coccoides et Clostridium leptum, ainsi que Faecalibacterium prausnitzii dans le microbiote du gros intestin avec conjointement des modifications sur sa biodiversité. En même temps, les quantités des produits finaux de la fermentation des acides aminés par le microbiote, les acides gras à chaîne courte (AGCC) et les acides gras à chaîne branchée sont fortement augmentées. Cependant, l'expression des transporteurs des acides monocarboxyliques et l'oxydation du butyrate par les colonocytes ne sont pas modifiés en lien avec des modifications mineures des concentrations en AGCC dues à une augmentation des contenus du gros intestin après l'ingestion du régime hyperprotéique. Il en résulte une augmentation de l'excrétion des AGCC dans les fèces. Ces phénomènes permettraient une homéostasie du métabolisme du butyrate dans les colonocytes, en lien avec le rôle crucial de cet AGCC sur l'épithélium du côlon. Dans la deuxième partie de cette thèse, nous avons testé l'effet d'un mélange d'acides aminés (Thr, Met et Glu) sur la cicatrisation de la muqueuse colique après une colite induite par le DSS (dextran sodium sulfate) ; un modèle d'étude des maladies inflammatoires intestinales souvent utilisé. Une optimisation de la cicatrisation de la muqueuse intestinale émerge comme une cible thérapeutique, dans la prise en charge de ces maladies. La colite a été induite chez le rat avec 5% (w/v) de DSS pendant 6 jours, puis, à l'arrêt du traitement DSS, les animaux ont soit reçu le mélange d'acides aminé soit l'Ala comme témoin iso-azoté, pendant 3, 7 et 10 jours. Nous avons observé que 10 jours de complément en mélange d'acides aminés améliorent la cicatrisation post-colite, avec des modifications sur le taux de synthèse protéique dans la muqueuse colique, sans toutefois modifier la résolution de l'inflammation. Nos résultats suggèrent que l'utilisation des mélanges d'acides aminés améliore la cicatrisation de la muqueuse colique après colite chimio-induite. / In industrialized countries, protein intake is largely higher than the recommended dietary allowance (RDA). Furthermore, high protein diets are used for their slimming effect by obese or overweight people. However, little is known regarding to the consequences of a high protein diet on the large intestinal ecosystem. We thus study the influence of a high protein diet on the microbiota, on the endoluminal composition of the large intestine and on the butyrate metabolism by isolated colonocytes. Rats received during 15 days either a high protein diet (53% of proteins) or a normo protein diet (14% of proteins). We observed that the quantity of major bacterial groups Clostridium coccoides and Clostridium leptum, but also Faecalibacterium prausnitzii was reduced in the microbiota of the large intestine together with modifications of its biodiversity. In the same time, the quantities of short-chain fatty acids (SCFA) and branched-chain fatty acids, final products of bacterial fermentation of amino acids, were increased. However, the expression of monocarboxylic acid transporters and butyrate oxidation in colonocytes remained unchanged, in association with minor changes of the SCFA concentrations due to marked increase of the weight of the large intestine content. We then observed an increase in the amount of SCFA in the feces. These phenomena would allow homeostatic metabolism of butyrate in colonocytes, in relationship with its crucial role on the colonic epitheliumIn. In the second part of this thesis, we have tested the effects of a mixture of amino acids (Thr, Met and Glu) on the colonic mucosa healing after colitis induced by DSS (dextran sodium sulphate); a model to study intestinal inflammatory bowel diseases largely used. Optimization of intestinal mucosa healing is more and more considered as a therapeutic goal. Colitis was induced in rats by 5% (w/v) DSS during 6 days, then at the end of the treatment with DSS, animals received either the amino acid mixture or Ala as iso-nitrogenous control, during 3, 7 or 10 days. We observed that 10 days amino acid mixture supplementation was able to improve the colonic mucosal healing, with modification of the protein synthesis rate, without however changes in the resolution of inflammation. Our results suggest that the supplementation with the amino acid mixture improve the mucosal healing after experimental colitis.