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Lactobacillus animalis LA51 and Bacillus sp. probiotics confer protection from the damaging effects of pathogenic Clostridium perfringens and Escherichia coli on the intestinal barrier.

G. Copani

Events

06-23-2020

Abstract:

265
Lactobacillus animalis LA51 and Bacillus sp. probiotics confer protection from the damaging effects of pathogenic Clostridium perfringens and Escherichia coli on the intestinal barrier.
G. Copani*, O. C. M. Queiroz, E. J. Boll. Animal Health and Nutrition, Chr. Hansen A/S H�rsholm, Denmark.

Toxins produced by Clostridium spp. can cause enteric disease in ruminant. The gut plays a key role in the digestion and absorption of nutrients and constitutes an initial organ exposed to external factors influencing the health of animals. Intestinal dysbiosis can promote overgrowth of different pathogens, which can cause intestinal barrier damage (leaky gut), which in turn may facility passage of toxins to the bloodstream. The objective of this study was to evaluate in vitro beneficial effects of different probiotic strains (Lactobacillus animalis (LA51), Bacillus licheniformis DSM5749 (BL) and Bacillus subtilis DSM5750 (BS)) on gut health in the presence of pathogens. Two assays were performed. For the adhesion assay, E. coli O157 (DSM17076) was added to intestinal Caco-2 cell monolayers (3�107 cfu/well) pre-incubated or not with BL or BS (1.5�109 cfu/well). E. coli adhesion was quantified by cfu enumeration using MacConkey agar plates incubated 18h at 37�C. For the “leaky gut” assay, transepithelial electrical resistance (TEER) was measured across Caco-2 monolayers exposed to live or dead LA51 (2x108 cfu/transwell) with or without Clostridium perfringens type a (CPa) (DSM756, 2x107cfu/transwell). FITC-dextran (FD) was added to the apical side of the Caco-2 cells after 5h of TEER measurements. The amount of FD translocated to the basolateral side was quantified after 5h by measuring the fluorescent signal. BL and BS reduced the binding of E. coli O157 to the cells by 78% and 51%, respectively (6.7�106 cfu/mL vs. 1.5�106 or 3.3�106 cfu/mL, P < 0.01). CPa caused a TEER decrease over the time, while live (but not dead) LA51 significantly reduced the TEER decrease (15 Ω cm2 vs. 150 Ω cm2, P < 0.01) and the amount of FD translocation (5.7% vs. 0.1%, P < 0.01). In conclusion, LA51 confers protection against Clostridium perfringens type a by counteracting its damaging effect on the intestinal integrity, while BL and BS reduce the adherence in vitro of pathogenic E. coli.

Keywords: Lactobacillus animalis, Clostridium perfringens, Bacillus licheniformis.