2018s teklad global 18 protein rodent diet

Six-week-old male C57BL/6J mice were purchased from Central Lab Animal Inc. (Korea) and maintained in a controlled atmosphere with a 12:12 h light and dark cycle. The mice were fed either a normal diet (ND; 2018S Teklad Global 18% Protein Rodent Diet; Envigo, USA) or a high-protein diet (a mixture of ND and milk protein blends; 6:4 w/w) for eight weeks. Mice (n = 24) were randomly divided into four groups: 1) ND; 2) High-protein diet (HPD); 3) HPD + L. rhamnosus IDCC 3201 (HPD + LLrh; 10⁷ CFU/day); 4) HPD + L. rhamnosus IDCC 3201 (HPD + HLrh; 10⁸ CFU/day). ND or HPD were supplied ad libitum, and L. rhamnosus IDCC 3201 was orally administered to mice daily. Animal studies were approved by the Institutional Animal Care and Use Committee of the Chungbook National University (approval number: CBNUA-1687-22-02). The body weight, and water and food consumption were measured weekly. After eight weeks, mice were subjected to a 6 h fasting period and anesthetized with diethyl ether. Blood samples were collected from the abdominal veins and centrifuged at 600 ×g for 20 min. The serum was collected and stored at −70°C until further use. To analyze free amino acids in serum, we employed a Hitachi L-8900 amino acid analyzer with a UV detector (Hitachi High-Technologies Corporation, Japan) and an ion-exchange column (#2622PH column 4.6 × 60 mm).

Male and female Sprague-Dawley (SD) rats were purchased from Envigo, UK. Rats were 7 to 8 weeks-old upon arrival in the animal unit. Rats were group-housed at 4 per cage in an environment controlled for light-dark cycle (12-h light; lights on at 7:00 a.m.), temperature (21 ± 1 °C) and humidity (55 ± 10%). Water and standard lab chow (2018S Teklad Global 18% Protein Rodent Diet, Envigo, Huntingdon, UK) were available ad libitum. All experiments were in full accordance with the European Community Council directive (86/609/EEC) and approved by the Animal Experimentation Ethics Committee of University College Cork (B100/3774). Animals were habituated to experimental conditions for a week prior to experiments taking place. On experimental day, animals were administered their respective treatment at the onset of the light phase and then placed in individual cages for duration of food intake monitoring. Food intake was then recorded by weighing the chow at defined intervals. For the gastro-protected pellets, animals were food restricted for a period of 4 h before a pre-weighed quantity of chow was added to the cages. The dosing system for pellets consisted of a flexible PVC gavage tube which was filled with a pre-weighed quantity of blank or active pellets. After insertion of the dosing tube a guidewire was used to administer the dose of pellets directly into the stomach.