Ingredient evidence profile
Bacillus subtilis
Bacillus subtilis evidence is strain-specific. The label name alone cannot establish that a product delivers the preparation or dose tested in research.
What is it?
Record the strain identifier as well as the species. A fermentation-product declaration should not be assumed to guarantee a particular live-organism count. Ask what is measured, when it is measured and whether the stated quantity lasts through shelf life.
Source and function
A bacterial species used in some microbial preparations; strain and preparation must be identified. Some preparations are tested as probiotics. A species name alone does not specify a live strain, viable dose or demonstrated benefit.
What does the research show?
A 2025 study tested strain ATCC PTA-122264 in 12 healthy adult female Beagles during an abrupt food change. The tested supplementation did not prevent the measured microbial shifts. Stool dry matter changed, while stool scores did not.
What the evidence cannot tell us
This was a small study of healthy Beagles under a particular feeding schedule. It cannot establish an effect for every B. subtilis strain, symptomatic dogs or other species. Funding and commercial involvement are described in the linked appraisal.
Questions to ask about a product
Request the exact strain, viable amount per serving, storage conditions and study on the finished preparation. Separate a measured microbiome change from a demonstrated improvement in how an animal feels or functions.
Safety and practical limits
This profile does not establish a universal dose or safety conclusion for probiotic use. Canine results must not be transferred to koi or goldfish merely because a fish-food label names the same bacterial species.
Sources and related reading
Bacillus subtilis during an abrupt diet change in dogs
Primary study source: 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.
Source checked 24 September 2026. Next review 24 December 2026. This is an initial summary built around the cited research, not a systematic review of all available studies.