Use of Different Synbiotic Strategies to Improve Gut Health in Dogs.

This study evaluated the effects of two synbiotic strategies on the intestinal microbiota and immune response in Beagle dogs. Twelve dogs were subjected to a crossover design with three diets: a control diet (CON), a diet supplemented with fiber and B. velezensis DSM 15544 (SYN), and the SYN diet with added porcine plasma (SYN+). Over three periods of seven weeks, fecal samples were analyzed for digestibility, short-chain fatty acids (SCFA), fecal markers, and microbiome composition, while blood samples were assessed for biochemical parameters, leucocytic counts including CD4/CD8 lymphocyte populations, and phagocytic activity. Both SYN and SYN+ diets increased the fecal volume without affecting the consistency and slightly reduced the organic matter and energy digestibility, while increasing SCFA concentrations and reducing branched-chain fatty acids. A microbiome analysis revealed no changes in the alpha diversity, but significant shifts in the beta diversity, with increases in beneficial taxa such as Faecalibacterium prausnitzii and reductions in potentially harmful bacteria like Prevotella copri. Immune response indicators showed increased fecal IgA and higher blood leukocyte counts, particularly lymphocytes and neutrophils, in the SYN diet group. Overall, both synbiotic strategies positively modulated the microbiota and immune response, though the addition of porcine plasma did not confer additional benefits.