Item – Theses Canada

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OCLC number
881137980
Link(s) to full text
LAC copy
LAC copy
Author
Mallet, Jean-Francois,1982-
Title
Modulation de NF-kappaB par Lactobacillus helveticus R389.
Degree
M. Sc. -- Université de Moncton, 2011
Publisher
Ottawa : Library and Archives Canada = Bibliothèque et Archives Canada, [2012]
Description
2 microfiches.
Notes
Comprend des références bibliographiques.
Abstract
<?Pub Inc> The human body can be compared to an ecosystem. Human cells coexist with approximately 1012 microorganisms on the skin and 10 14 microorganisms in the digestive track. To put this number in perspective, it is generally accepted that the body is composed of 1013 human cells. The entire population of microorganisms present in the digestive tract is named microbiota or gut flora. It is now clear that a relation between the microbiota and the host exists because bacteria present in the intestine permit an adequate absorption of nutrients, a maturation of the immune system and regulate the proper development of the gut. Many microorganisms are used in the production of food around the world like yogurts, kefir and kombucha. Microorganisms that have benefits for the host are named probiotics. 'Lactobacillus helveticus' is used in many fermented products like Swiss cheese, Italian cheese and fermented milks. The wide usage of this bacterium in cheese making is explained by its ability to prevent bitterness and it also adds a nutty and oaky flavor to fermented products. The consumption of probiotics can reduce the duration of diarrhea associated with antibiotics, control inflammation and prevent the incidence of certain cancers. 'L. helveticus' R389 influences the production of many pro- and anti- inflammatory cytokines. It was demonstrated before in ' ex vivo' experiments that 'L. helveticus' R389 interacts partially with TLR-4. With this knowledge, we postulated that 'L. helveticus ' R389 influences the production of cytokines by initiating the translocation of NF-[kappa]B. NF-[kappa]B is an important signaling pathway in inflammation and cancers. We tested, on female Balb/c mice, the effect of the consumption of milk fermented with 'L. helveticus' R389 for 7 days on the translocation of 2 sub-units of NF-[kappa]B and 2 mediators of inflammation in an' Escherichia coli' MM294 challenge test. The Western blot analysis revealed that the consumption of milk fermented by 'L. helveticus' R389 prevents the translocation to the nucleus of the NF-[kappa]B sub-units P50 and P65 in epithelial intestinal cells. The diminution of the inflammatory signals IL-6 and CCL3 in the cultured cells supernatant confirm the Western blot results. A partial explanation for ' L. helveticus' R389 beneficial properties can be attributed to its action on the NF-[kappa]B pathway but the intermediaries are still not resolved.
ISBN
9780494812112
0494812117