PSIX-16 Effects of Bacillus coagulans GBI-30, 6086 on nutrient digestibility, fecal characteristics and metabolites, immunity, and microbiota of healthy adult dogs subjected to an abrupt diet change
Authors: Wilson Sofia M , Kang Yifei , Wren Jocelyn , Millette Mathieu , Kelly Melissa , Vinay Elena , Menton John , Swanson Kelly S 
Published: September 2024

Abstract
Probiotics are defined as live microorganisms that confer a health benefit on the host when administered in adequate amounts. Bacillus coagulans GBI-30, 6086 (BC30) is a commercially available, lactic acid-producing, spore-forming bacteria that exhibits diverse functions. Contrary to most lactic acid-producing bacteria, B. coagulans spores can withstand extreme conditions, lending resiliency through commercial pet food processing, storage, and chemical and enzymatic digestion through the gastrointestinal tract. Previous studies in humans and livestock suggest B. coagulans have probiotic potential, although research in dogs is limited. Therefore, the objectives were to determine the effects of B. coagulans on nutrient digestibility, hematology, immunoglobulin concentrations, and fecal characteristics, metabolites, and microbiota populations of healthy adult dogs before and after an abrupt diet change. Pointer dogs [n = 12; age = 5.9 ± 2.5 yr; body weight (BW) = 26.6 ± 6.1 kg] were used in a replicated 3 × 3 Latin square design and fed commercial diets containing no probiotics or prebiotics. Probiotic or placebo capsules were administered before each daily feeding, with the following treatments tested: 1) basal diet + placebo (control; 250 mg maltodextrin); 2) basal diet + B. coagulans (low dose; 5 x 108 CFU/d); and 3) basal diet + B. coagulans (high dose; 2.5 x 109 CFU/d). An extruded kibble diet was fed to all dogs during a 28-d diet transition phase, after which dogs were abruptly switched to a commercial canned diet with fecal samples collected 2-, 6-, 10-, and 14-d after diet change. All data were analyzed using the Mixed Models procedure of SAS 9.4, with P &lt; 0.05 being significant. Prior to dietary change, nutrient digestibility, food intake, immunoglobulin concentrations, metabolites, and hematology were not affected by treatment. However, fecal scores were decreased (P &lt; 0.05; firmer stools) in dogs fed B. coagulans than controls. Also, fecal Faecalibacterium abundance was greater (P &lt; 0.05) in dogs fed the low B. coagulans dose than those fed the high dose or controls. There were no interaction effects observed due to B. coagulans supplementation throughout the diet transition, but the abrupt transition to canned food reduced (P &lt; 0.0001) fecal DM content and increased (P &lt; 0.0001) fecal scores (looser stools) and pH. The diet transition also increased (P &lt; 0.01) fecal Clostridium hiranonis, Collinsella, Fusobacterium, and Ruminococcus gnavus abundances and decreased (P &lt; 0.01) fecal Bifidobacterium, Blautia, Faecalibacterium, Prevotella copri, Streptococcus, and Turicibacter abundances. Abundances of E. coli, Faecalibacterium, and Prevotella copri were modulated (P &lt; 0.05) by B. coagulans supplementation alone. Our results demonstrate that although B. coagulans did not appear to attenuate shifts in fecal consistency and microbiota populations during an abrupt dietary change, this species may aid in maintaining stool quality and does not negatively impact nutrient digestibility or canine health.