title: Old beagle dogs have lower faecal concentrations of some fermentation products and lower peripheral lymphocyte counts than young adult beagles.
abstract: The effects of age on microbiota composition, gut fermentation end-product formation and peripheral lymphocyte numbers were compared between old and young adult Beagle dogs fed four kibble diets differing in yeast cell wall contents. The experiment had a double 4 × 4 Latin square design, one with four mature dogs (4 years old) and the other with four old dogs (10 years old), with four replicates (diets) per dog. In each period a 15 d adaptation period preceded a 5 d total collection of faeces for the digestibility trial. On day 21, fresh faecal samples were collected for the determination of bacterial enumeration, pH, biogenic amine and short-chain fatty acid. Flow cytometry was used for immunophenotypic evaluation. Dogs were fed four kibble diets with similar composition with 0, 0.15, 0.30 and 0.45 % of yeast cell wall (as-fed), respectively. Data were evaluated using general linear models of Statistical Analysis Systems statistical software (P < 0.05). No evidence of a difference in faecal bacteria counts between ages was found (total aerobes, total anaerobes, Bifidobacterium, Lactobacillus, Clostridium and Escherichia coli: P>0.15). Faecal concentrations of butyrate, histamine, agmatine and spermine were lower (P ≤ 0.05) and faecal pH was higher (P = 0.03) in older dogs than in mature adult dogs, suggesting an alteration in bacterial metabolic activity, or in the rate of intestinal absorption of these compounds. Concentrations of T-lymphocytes, T-cytotoxic lymphocytes and B-lymphocytes were also lower (P ≤ 0.01) in older dogs than in mature adult dogs. The study confirmed alterations in peripheral lymphocytes and revealed a reduced concentration of some fermentation end products in the colon of old dogs.
authors: Veterinary Medicine and Surgery Department, College of Agrarian and Veterinarian Sciences, São Paulo State University - UNESP, Via de Acesso Prof. Paulo Donato Castellane, SP 14.884-900, Brazil.
authors: Márcia de Oliveira Sampaio
authors: Mde O
authors: Gomes
authors: Mariana Casteleti
authors: MC
authors: Beraldo
authors: Thaila Cristina
authors: TC
authors: Putarov
authors: Márcio Antônio
authors: MA
authors: Brunetto
authors: Leandro
authors: L
authors: Zaine
authors: Maria Beatriz Abreu
authors: MB
authors: Glória
authors: Aulus Cavalieri
authors: AC
authors: Carciofi
mesh_terms: D000375:Aging / Q000502:physiology*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000502:physiology; D004285:Dogs / Q000502:physiology*; D005243:Feces / Q000737:chemistry*; D005285:Fermentation / Q000502:physiology*; D018655:Lymphocyte Count / Q000662:veterinary*