Biavati, B.; Modesto, M.; Stefanini, I.; D'Aimmo, M. R.; Mazzoni, M.; Trevisi, P.; Tittarelli, C.; Bosi, P.; Strozzi, G. P.; Allesina, S.; Deidda, F.; Barba, M. and Lorenzini, P. (2007) Dietary Nitrate: Effects on the health of weaning pigs and Antimicrobial activity on seven probiotic Bifidobacterium spp. strains. Paper at: 3rd QLIF Congress: Improving Sustainability in Organic and Low Input Food Production Systems, University of Hohenheim, Germany, March 20-23, 2007.
The potential role of nitrite as an antimicrobial substance in the stomach may be of some importance in the ecology of the gastrointestinal tract and in host physiology. It has been shown that nitrite, under the acidic conditions of the stomach, may kill gut pathogens like Salmonella enteritidis, Escherichia coli, Salmonella typhimurium, and Yersinia enterocolitica, whereas acid alone has only a bacteriostatic effect. An in vivo study was conducted in order to assess the effects of dietary nitrate on microbiota and on the health of the gut (particularly in the stomach and small intestine). 96 weaning pigs were fed a diet containing high nitrate levels (15 mg and 150 mg) and then challenged with Salmonella enterica serovar typhimurium.
Differences in composition of the gut microbiota were assessed by analysing samples from the pigs: To date analysis of 48 pigs has been completed.. Preliminary results demonstrated no effect on the population densities of microbial groups either from the challenge or from nitrate intake. However, increasing the time from challenge decreased either the counts of LAB in the stomach and jejunum or of clostridia in the stomach.
Bifidobacteria also decreased in the stomach contents as nitrate supplementation increased. Supplementing the feedstuff with high dietary nitrate intake and then challenging with Salmonella did not affect the gastric pH or the degree of ulceration in the pigs.
The synergistic bactericidal effects of pH, nitrite and thiocyanate on seven probiotic Bifidobacterium spp. strains were also investigated in an in vitro study.
The results of the in vitro study demonstrated that an inhibitory effect exists on the seven probiotic bifidobacteria investigated with an exposure longer than 2 hours and pH values < 5.0. Addition of thiocyanate also increased the susceptibility of the tested strains. In this in vitro study, the most resistant strains at all conditions were B. animalis subsp. lactis Ra 18 and P32 and B. choerinum Su 877, Su 837 and Su 891.
|EPrint Type:||Conference paper, poster, etc.|
|Type of presentation:||Paper|
|Keywords:||Nitrate, isothiocyanate, probiotic bifidobacteria, pigs, gut microbiota|
|Subjects:|| Animal husbandry > Health and welfare|
Animal husbandry > Feeding and growth
|Research affiliation:|| International Conferences > 2007: 3rd QLIF Congress > 4 Livestock production|
European Union > QualityLowInputFood > Subproject 4: Livestock production systems
|Deposited By:||Modesto, Doc Monica|
|Deposited On:||05 Mar 2007|
|Last Modified:||12 Apr 2010 07:34|
|Additional Publishing Information:|| The final version of this paper is published in: |
Niggli, Urs; Leifert, Carlo; Alföldi, Thomas; Lück, Lorna and Willer, Helga, Eds. (2007) Improving Sustainability in Organic and Low Input Food Production Systems. Proceedings of the 3rd International Congress of the European Integrated Project Quality Low Input Food (QLIF). University of Hohenheim, Germany, March 20 – 23, 2007. Research Institute of Organic Agriculture FiBL, CH-Frick.http://orgprints.org/10417/
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