Influência da ingestão de Bifidobacterium breve carreada no leite humano na modulação da microbiota intestinal, na histomorfometria do cólon, na produção de citocinas e de espécies reativas do oxigênio e do nitrogênio em modelo murino

• Ano de defesa: 2006
• Autor(a) principal: Ramos, Maria da Penha Píccolo
• Orientador(a): Ferreira, Célia Lúcia de Luces Fortes
• Banca de defesa: Carlos, Iracilda Zeppone , Franceschini, Sylvia do Carmo Castro
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Leite materno; Probiótico; Intestino grosso; Citocinas
• Palavras-chave em Inglês: Human milk; Probiotic; Large intestine; Cytokines
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/470

The objectives of this work were to evaluate the microbial groups present in the human milk obtained from voluntary donors during a 10- to-30 day-lactating period and their importance in human milk banks, as well as to verify the pH and process of modulation of the different microbial groups present in the cecal content in the murine model, by means of ingesting pasteurized human milk, added Bifidobacterium breve or not; to analyze histomorpho metrically the ascending colon region by determining the intestinal crypt depth and verify the animals immunological response by means of ingesting pasteurized human milk added Bifidobacterium breve or not, in the peritoneal exudates and splenic cells for quantification of cytokines, nitrogen and oxygen intermediary compounds. The trial was divided into four phases: In the first, the donors were registered in the hospital and human milk was home collected; hygiene-sanitary quality was determined by means of total coliform, total aerobe mesophyll and Staphylococcus aureus quantification and pH determination in raw and pasteurized human milk samples. In the second phase, seven bifid bacteria strains (UFVCC 1083, 1091, 1099, 1103, 1105, 1108 and 1111) were selected to compose the probiotic pool that was added to the pasteurized milk fed daily to the animals. In the third phase of the experiment, 48 21-to-23 day old Wistar females were used in each repetition, divided into four experimental groups: Basal; Control (diet); PM (pasteurized human milk) and BAPM (pasteurized human milk added bifid bacteria). The four animals composing the basal group were sacrificed on the first day of the experiment (T0) and the animals composing the other groups were daily fed different diets (0.1 mL) orally using sterilized micro pipettes during 21 days and later sacrificed; pH was determined and the modulation of the microbial groups present in the cecal region was verified by means of determining bifid bacteria, clostridia, Lactobacillus spp., total coliform and total aerobe mesophyll counts, together with histomorphometric analysis of the ascending colon region of these animals by determining the intestinal crypt depth; finally, in the fourth phase of the experiment, 36 Wistar females were used and daily fed (0.1 mL) orally, using sterilized micropipettes, under different treatments, as follows: Control (diet); PM (pasteurized human milk) and BAPM (pasteurized human milk added bifid bacteria), during 30 days. These animals were later killed to determine immunological response by means of determination of the cytokines IL-4, IL-6, IFN-γ, TNF-α; cellular cytotoxicity, determination of nitrogen (NO), and oxygen (H2O2) intermediary compounds in the supernatant of the peritoneal and splenic exudate cells. It was concluded that despite the pasteurization process efficiency for pathogens verified in this study, donors are urgently advised to become aware of the methods used for human milk collection. More rigorous monitoring measures of hygiene-sanitary quality control should be adopted for human milk collected at home, since such measures are essential to ensure safe food for the newly born. A medium increase in the crypt length was verified with age, being more pronounced in the animal group fed pasteurized milk (PM) and the results also showed that the addition of bifid bacteria to the human milk (BAPM) did not present any risk of altering ascending colon histomorphometry, as to the parameter evaluated. Such information underlies the fact that adding bifid bacteria to pasteurized milk in the human milk banks does not interfere in epithelium integrity and has a potential to benefit the children who need to make use of this alternative. It was also concluded that bifid bacteria added to pasteurized milk (BAPM) exerted an antagonist effect for total coliforms in micro biota modulation in the cecal content, compared to the other treatments (PM and control). It was also verified that the bifid bacteria did not present oral toxicity in relation to macrophage viability and did not promote any adverse effect on the health of the animals tested. Finally, adding bifid bacteria to the diet has influenced the immunological system of the animals by releasing the mediators presented. The accumulation of information on the beneficial effects of these probiotic bacteria has justified their addition to several products, including pasteurized milk, under the form of frozen concentrated human milk found in the human milk banks, offered as an alternative by the Brazilian public health system. The evidences showing the benefits originated from the use of probiotic bifid bacteria justify further studies on their mode of action, in order to optimize their use as prophylactic and immune modulating agents.