Independent study appraisal · 2025
Bacillus subtilis during an abrupt diet change in dogs
This specific probiotic did not prevent the measured microbial changes during the tested food transition.
Question and design
12 healthy adult spayed female Beagles; replicated 3 × 3 Latin square. The named strain at 1 or 5 billion CFU daily; 28 days on high-fibre kibble followed by 14 days on a high-protein, high-fat canned diet. Comparator: Maltodextrin control.
What was measured?
Faecal scores, dry matter, pH, microbiota and dysbiosis index.
Main findings
Supplementation did not attenuate the microbial shifts after the diet change. Diet change reduced faecal dry matter and altered microbial communities, without significantly changing stool scores.
Strengths and limitations
A control, two doses, crossover structure and repeated sampling. Small, healthy, single-breed population; no gradual-transition arm. Findings apply to the tested strain, doses and food switch.
Researchers’ conclusion
The authors call for further strain- and dose-specific investigation.
Evidence.pet interpretation
A changed microbiome is not automatically a clinical illness. A null result here neither validates other probiotics nor proves that all probiotics are ineffective.
Funding and conflicts
Kerry Group funded the study, contributed to design and manuscript revision, and employed three authors; another author consulted for Kerry.
Source and connected records
Oba PM et al. Evaluation of Bacillus subtilis ATCC PTA-122264 on the fecal characteristics and microbiota of healthy adult dogs subjected to an abrupt diet change. Frontiers in Veterinary Science. 2025;12:1617072.
Read the primary source · DOI record
STU-024. Checked 24 September 2026. Next review 24 December 2026. Full-text editorial appraisal; broader ingredient review ongoing.