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.
Research on this ingredient
Dog
Bacillus subtilis ATCC PTA-122264 in healthy dogs
One study with 2 reviewed arm or dose connection(s).
Arm pta_122264_1_billion_cfu
Bacillus subtilis ATCC PTA-122264 in healthy dogs
Direct · dog. 12 healthy adult Beagles in a replicated Latin-square feeding experiment.
Tested form: Bacillus subtilis strain ATCC PTA-122264 supplied as a daily supplement. Dose: 1 billion CFU/day (Colony-forming units per dog per day; oral supplementation with kibble). Duration: 28-day experimental periods. Comparator: Maltodextrin placebo with the kibble diet.
Measured finding: Most stool and general-health measures did not change. Three taxa were lower at the lower dose; some digestibility measures showed trends rather than statistically significant improvement.
Limitations: 12 healthy Beagles; limited treatment periods. Some findings were trends and were not significant at the 5% level. Other strains and commercial formulations were not established as equivalent.
Arm pta_122264_5_billion_cfu
Bacillus subtilis ATCC PTA-122264 in healthy dogs
Direct · dog. 12 healthy adult Beagles in a replicated Latin-square feeding experiment.
Tested form: Bacillus subtilis strain ATCC PTA-122264 supplied as a daily supplement. Dose: 5 billion CFU/day (Colony-forming units per dog per day; oral supplementation with kibble). Duration: 28-day experimental periods. Comparator: Maltodextrin placebo with the kibble diet.
Measured finding: Most stool and general-health measures did not change. Three taxa were lower at the lower dose; some digestibility measures showed trends rather than statistically significant improvement.
Limitations: 12 healthy Beagles; limited treatment periods. Some findings were trends and were not significant at the 5% level. Other strains and commercial formulations were not established as equivalent.
Sailfin_molly
Bacillus-enriched Artemia in sailfin molly feeding
One study with 1 reviewed arm or dose connection(s).
Arm b_subtilis_enriched_artemia
Bacillus-enriched Artemia in sailfin molly feeding
Multi ingredient · sailfin_molly. Sailfin molly in commercial-feed, unenriched-Artemia and Bacillus-enriched-Artemia groups.
Tested form: Bacillus subtilis delivered through enriched Artemia. Dose: 1 x 10^5 CFU/mL added to Artemia culture water daily (Culture-water concentration used to enrich Artemia; not a direct fish-food dose). Duration: Not reported in reviewed abstract. Comparator: Commercial-feed control and unenriched Artemia.
Measured finding: Growth did not differ between groups. The enriched-Artemia group showed improved reproductive and fry-survival measures, more intestinal Bacillus and lower challenge mortality. These combined-treatment findings do not isolate the effect of Artemia or Bacillus alone.
Limitations: Species-specific combined treatment and experimental challenge; strain, sample size and duration are not established in the reviewed abstract. Generic dry-food Bacillus inclusion is a different delivery method.
This ingredient was part of a combined formulation; the study does not isolate its contribution.
Products listing or mentioning this ingredient
No reviewed product connections are available for display in the current recipe context. This does not establish that products exclude this ingredient.
PRACTICAL READING
Related guides
Read a focused explanation connected to this record.
- How to judge the evidence behind a pet supplement claimCheck whether research studied the finished product, the same animal, the same ingredient form and dose, and an outcome that matters.