In Vitro Fermentation Characteristics of Prebiotics by Canine Probiotic Bacterial Species

To determine the probiotic potential of canine colonic bacterial species (Bifidobacterium pseudolongum [B] and Lactobacillus murinus ruminis [L]), an in vitro study of 3 prebiotic substrates (fructooligosaccharides [FOS], galactooligosaccharides [GOS], and lactosucrose [LS]) and beet pulp (BP; a standard fiber in premium canine diets) was conducted. Thus, 240 serum bottles (125 mL; 192 for substrates and 48 for blanks) were used in a completely randomized design experiment with treatments being arranged as a 3 (inocula) × 4 (substrates) factorial. The bottles with (0.3 g dry matter [DM]) or without (blanks) substrates had 27 mL of anaerobic medium and 3 mL of inoculum (B, L, or B and L at 1:1 ratio; 6 h growth in tryptic soy broth at 39°C) and were incubated at 39°C for 3, 6, 9, 12, 15, 18, 21, or 24 h (8 replications/treatment). Across substrates, extent of DM disappearance was similar (79.4%) among the 3 inocula but gas production was highest (P < 0.05) for B (93.6 mL) and similar for L and BL (34.2 mL). Lactate concentration was highest (P < 0.05) for L and BL (290.5 μg/mL) and lowest (P < 0.05) for B (200.6 μg/mL). Across inocula, extent of DM disappearance was higher (P < 0.05) for prebiotics (98.7%) than for BP (21.3%) and gas production was lowest (P < 0.05) for BP (13.2 mL), highest (P < 0.05) for FOS (88.8 mL), and intermediate (P < 0.05) for GOS and LS (56.9 mL). Lactate concentration was highest (P < 0.05) for GOS (344.1 μg/mL), lowest (P < 0.05) for BP (107.8 μg/mL), and intermediate (P < 0.05) for FOS and LS (295.1 μg/mL). The results suggest L to have the highest probiotic potential and GOS to have the highest prebiotic potential.