2 fucosyllactose

Bifidobacterium strains were routinely cultured at 37 °C in Wilkins-Chalgren Anaerobe Broth (Oxoid, Basel, Switzerland) supplemented with soya peptone (5 g L⁻¹, Oxoid), Tween 80 (1 mL L⁻¹, Sigma-Aldrich, Buchs, Switzerland), and fresh sterile filtered l-cysteine hydrochloride (0.5 g L⁻¹, Sigma-Aldrich). Carbohydrate utilization profile of bifidobacteria was investigated in API 50CHL Medium (10 g L⁻¹ bovine/porcine origin polypeptone, 5 g L⁻¹ yeast extract, 1 mL⁻¹ Tween 80, 2 g L⁻¹ dipotassium phosphate, 5 g L⁻¹ sodium acetate, 2 g L⁻¹ di-ammonium citrate, 0.2 g L⁻¹ magnesium sulphate heptahydrate, 0.05 g L⁻¹ manganese sulphate monohydrate, 0.17 g L⁻¹ bromocresol purple; BioMérieux, Genève, Switzerland). The pH of the API medium was adjusted to 7.5 to obtain a final pH of 7 after autoclaving at 121 °C for 15 min. Carbohydrates (concentration as indicated) were filter sterilized and added after autoclaving. Fresh sterile filtered l-cysteine hydrochloride was always added before cultivation (0.5 g L⁻¹). Glucose, lactose, and L-fucose were obtained from Sigma-Aldrich, 2′-fucosyllactose (2′-FL, Fucα1-2Galβ1-4Glc), 3′-fucosyllactose (3′-FL, Fucα1-3Galβ1-4Glc), 3′-sialyl-lactose (3′-SL, NeuAcα2-3Galβ1-4Glc), 6′-sialyl-lactose (6′-SL, NeuAcα2-6Galβ1-4Glc), Lacto-N-neotetraose LNnT (Galβ1-4GlcNacβ1-3Galβ1-4Glc) were donated by Glycom A/S (Lyngby, Denmark).

Treatment through oral administration via drinking water of carvacrol, deferoxamine, deoxycholic acid (all from Sigma-Aldrich, Munich, Germany), 2′-fucosyl-lactose (Chr. Hansen HMO GmbH, Rheinbreitbach, Germany), and the quadruple combination commenced 2 days following the onset of C. jejuni infection. Dosages were calculated considering an average body weight of approximately 25 g per mouse and an estimated drinking volume of 5 mL per day. All compounds were dissolved in autoclaved tap water. The daily doses and their previously determined minimal inhibitory concentrations (MICs) are illustrated in Table 1. To enhance the water solubility of carvacrol, 50 mg of the compound were dissolved in 250 μL Tween^® 80 (Sigma-Aldrich, Munich, Germany). The placebo group received vehicle dissolved in autoclaved tap water.