Effet chez le porcelet d'une exposition à un régime co-contaminé en ...

INTRODUCTIONwall peptidoglycans and polysaccharides have been suggested to be the two most importantelements responsible for the binding by lactic acid bacteria. According to Haskard et al. (2001) andPeltonen et al. (2001), Lactobacillus amylovorus strains and Lb. rhamnosus strains removed morethan 50% AFB 1 .Furthermore, probiotics such as Lactobacillus rhamnosus strain GG and a mixture of Lactobacillusrhamnosus LC705 and Propionibacterium freudenreichii ssp. shermanii JS (LC705+JS) wereinvestigated in order to know whether these probiotic bacteria bind AFB 1 under physiologicalconditions in the gut. Results concluded that both probiotic preparations were able to bind AFB 1 invitro (Gratz, 2007). Studies carried out by Pierides et al. (2000) suggested that six dairy strains oflactic acid bacteria can reduce AFM 1 content in liquid media. Their ability to bind AFM 1 gave apotential approach for either decontamination of foods and feeds or reduction of the bioavailabilityof aflatoxins in the diet, presuming that the bacteria are able to remove the toxin from thegastrointestinal tract.Several successful studies were conducted with bacteria regarding binding of zearalenone. Theinteraction between two Fusarium mycotoxins, zearalenone and its derivative zearalenol with twostrains of Lactobacillus was investigated by El-Nezami et al. (2002b). After mycotoxin incubation (2mg/ml) with two strains of Lb. rhamnosus, approximately 55% of the toxins were bound instantlyafter mixing with the bacteria. The mechanism linking these toxins to the surface of bacteria wasshown not to be due to metabolic activity of living cells. In addition, removal of ZEA from medium byfive Propionibacterium, three Lactobacillus and two Bifidobacterium strains has shown to be possible.All examined strains caused a decrease of toxin concentration in medium after incubation with both,viable and nonviable cells. Usually higher efficiency was observed with Propionibacteria (El-Nezami etal., 2002a; Gwiazdowska et al., 2006). Lactobacillus and Propionibacterium also removedtrichothecenes (DON, 3-AcDON, NIV, FX, DAS, T-2) from liquid media (El-Nezami et al., 2002a).A trial conducted by El-Nezami et al. (2000) indicated that probiotic lactic acid bacteria arecapable of binding AFB 1 under in vivo conditions. They observed that in the presence of Lb.rhamnosus GG 74% of the reduction in the uptake of AFB 1 by the intestinal tissue takes place within60 min. Also, probiotic Lb. rhamnosus GG administration in rats demonstrated that fecal AFB 1excretion in GG-treated rats was increased via bacterial AFB 1 binding and that AFB 1 -associatedgrowth faltering and liver injury were alleviated with GG treatment (Gratz et al., 2006).f) Other organic adsorbentsOther organic adsorbents such as humic acid, divinylbenzene-styrene, chlorophyllin, alfalfa andfibers were studied. Van Rensburg (2006) investigated oxihumate (pure, high quality humic acid)82