Glucose-Lowering Effects and Safety of Bifidobacterium longum CKD1 in Diabetic Dogs and Cats

Diabetes mellitus is a common endocrine disorder in dogs and cats, and achieving stabilization with insulin alone can be challenging. This study evaluated the glucose-lowering efficacy and safety of <i>Bifidobacterium longum</i> CKD1 in diabetic companion animals. Nine dogs and 13 cats received <i>B. longum</i> CKD1 daily for 12 weeks. Fasting blood glucose (FBG) levels decreased by 26.2% in dogs and 18.0% in cats. Remarkable improvement in FBG was observed in dogs and cats with baseline levels exceeding 200 mg/dL in dogs and 250 mg/dL in cats. Notably, dogs exhibited a significant 61.8% reduction (<i>p</i> < 0.05), while cats showed a 38.4% decrease. Insulin-treated cats required significantly lower insulin doses by Week 12 (<i>p</i> < 0.05). Continuous glucose monitoring in cats demonstrated a 21.6% reduction in mean glucose levels and a significant 32.3% decrease in the time spent with glucose levels above 181 mg/dL (<i>p</i> < 0.05). Microbiota analysis revealed an increase in beneficial commensals and short-chain fatty acid producers, along with a reduction in pathobionts. No treatment-related adverse effects were observed. These findings indicate that <i>B. longum</i> CKD1 improves glycemic control and safely modulates the gut microbiota, supporting its potential use in managing diabetes mellitus in companion animals.