Bacillus coagulans is a spore-forming bacterium that shows up in ten products on this site, more than almost any other spore species we track. Two dog studies exist: one found a low dose produced slightly firmer stools and higher fecal bacterial diversity during an abrupt diet change, without meaningfully shifting most other gut microbiota; the other found it combined with B. subtilis eased allergic dermatitis symptoms and sped wound healing. Neither study tested it for diarrhea treatment or inflammatory bowel disease, so don't read either one as evidence of GI-disease efficacy.
PubMed and PMC, dogs only. Other species are listed separately below and don't count toward the badge.
We don't have a confirmed CFU-per-kg dose number for Bacillus coagulans from the canine trials yet (5x10^8 to 2.5x10^9 CFU/day tested alone in a diet-change fecal study (Wilson 2025, PMID 41304148); 10^9 CFU/day tested combined with B. subtilis in a dermatitis study (Khosravi 2024, PMID 38501344) -- roughly 10^8-10^9 CFU/day range tested in dogs so far.) -- so this calculator is intentionally disabled rather than guessing.
In a 12-dog study, a low dose modestly firmed stool and raised fecal bacterial diversity during an abrupt diet change, though it didn't meaningfully change most other microbiota shifts. In a separate 20-dog trial, it was given together with Bacillus subtilis for allergic contact dermatitis, where the combination reduced symptoms and sped wound repair.
No. Neither of the two dog trials we found tested it for GI-disease treatment — one was about diet-change fecal quality, the other about skin dermatitis — so there isn't evidence yet that it treats diarrhea or inflammatory bowel disease.
Doses ranged from about 5x10^8 to 2.5x10^9 CFU/day when tested alone, and 10^9 CFU/day when combined with B. subtilis — roughly the 10^8 to 10^9 CFU/day range tested in dogs so far.