What the evidence says. Early or small human trials; promising but not yet conclusive.
What is Bacillus subtilis?
Bacillus subtilis (Bacillus subtilis (DE111 / R0179)) is a probiotic strain used for reduces days of vomiting and hard stools / occasional gi discomfort in young children (de111, 1 billion cfu/day). NutriDex grades the human evidence as Preliminary. Bacillus subtilis is a spore-forming probiotic whose acid-resistant spores survive gastric transit; both DE111 and R0179 designations have been shown in human RCTs to reach and germinate in the small intestine and to be well tolerated. The strongest data are for digestive comfort: in a 2021 RCT of 102 daycare children, DE111 (1 billion CFU/day x 8 weeks) reduced days of vomiting and hard stools versus placebo. In healthy adults, a 2021 pilot RCT (n=44) found DE111 enhanced regulatory T-cell responses but left most GI symptom and inflammation markers largely unchanged, and a 2015 R0179 dose-ranging trial (n=81) confirmed tolerability and GI survival without persistent microbiota shifts. Overall the human evidence is positive but small and pilot-grade — no large meta-analyses yet exist for these specific strains.
Purported Benefits
✓Reduces days of vomiting and hard stools / occasional GI discomfort in young children (DE111, 1 billion CFU/day)
✓Eases occasional constipation and diarrhea / improves daily bowel-movement profile in healthy adults
✓Enhances regulatory immune responses (increased CD25+/FoxP3+ Tregs after LPS challenge) in healthy adults (DE111)
✓Survives gastric transit and germinates in the small intestine (spore-based delivery; DE111, R0179)
✓May improve body-fat percentage when combined with resistance training in female athletes (DE111, 5 billion CFU/day)
✓May attenuate circulating pro-inflammatory TNF-alpha in trained athletes (DE111)
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
Typically 1 billion CFU/day (DE111) for GI/pediatric use, up to 5 billion CFU/day in athlete trials; R0179 well tolerated from 0.1 to 10 billion CFU/day. Taken once daily as a shelf-stable spore capsule, with or without food, over 4-8 weeks in trials.
Active Compounds
DE111 (Deerland, branded spore strain; 1-5 billion CFU)R0179 (Lallemand/Rosell dose-ranging strain)BS50, DG101 (other studied B. subtilis strains)Acid-resistant spore capsules, gummies, and shelf-stable powders (no refrigeration needed)
Safety & Cautions
⚠
Well tolerated across all human trials, including children 2-6 years and adults up to 10 billion CFU/day; reported adverse events (mild flatulence, transient constipation/diarrhea) were non-severe and similar to placebo. As with any live probiotic, use caution in critically ill, severely immunocompromised, or central-venous-catheter patients given theoretical bacteremia risk. Spores are cleared from the gut shortly after dosing stops and do not durably colonize. Educational only — always check with your doctor or pharmacist before combining Bacillus subtilis with any medicine.
Bacillus subtilis is most often taken for Reduces days of vomiting and hard stools / occasional GI discomfort in young children (DE111, 1 billion CFU/day), Eases occasional constipation and diarrhea / improves daily bowel-movement profile in healthy adults, Enhances regulatory immune responses (increased CD25+/FoxP3+ Tregs after LPS challenge) in healthy adults (DE111), Survives gastric transit and germinates in the small intestine (spore-based delivery; DE111, R0179). Shelf-stable spore-forming probiotic with promising but still-preliminary human GI and immune data
Does Bacillus subtilis work — what does the evidence say?
Preliminary evidence. Early or small human trials; promising but not yet conclusive. Bacillus subtilis is a spore-forming probiotic whose acid-resistant spores survive gastric transit; both DE111 and R0179 designations have been shown in human RCTs to reach and germinate in the small intestine and to be well tolerated. The strongest data are for digestive comfort: in a 2021 RCT of 102 daycare children, DE111 (1 billion CFU/day x 8 weeks) reduced days of vomiting and hard stools versus placebo. In healthy adults, a 2021 pilot RCT (n=44) found DE111 enhanced regulatory T-cell responses but left most GI symptom and inflammation markers largely unchanged, and a 2015 R0179 dose-ranging trial (n=81) confirmed tolerability and GI survival without persistent microbiota shifts. Overall the human evidence is positive but small and pilot-grade — no large meta-analyses yet exist for these specific strains.
What is the typical dose of Bacillus subtilis?
Typically 1 billion CFU/day (DE111) for GI/pediatric use, up to 5 billion CFU/day in athlete trials; R0179 well tolerated from 0.1 to 10 billion CFU/day. Taken once daily as a shelf-stable spore capsule, with or without food, over 4-8 weeks in trials.
Is Bacillus subtilis safe? Any cautions or side effects?
Well tolerated across all human trials, including children 2-6 years and adults up to 10 billion CFU/day; reported adverse events (mild flatulence, transient constipation/diarrhea) were non-severe and similar to placebo. As with any live probiotic, use caution in critically ill, severely immunocompromised, or central-venous-catheter patients given theoretical bacteremia risk. Spores are cleared from the gut shortly after dosing stops and do not durably colonize.
How many studies support Bacillus subtilis?
NutriDex cites 9 sources for Bacillus subtilis, graded "Preliminary".
Cite this page
APA
Peh, D. (2026). Bacillus subtilis (Bacillus subtilis (DE111 / R0179)): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/bacillus-subtilis
BibTeX
@misc{nutridex_bacillus_subtilis,
author = {Peh, Daryl},
title = {Bacillus subtilis (Bacillus subtilis (DE111 / R0179)): Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/bacillus-subtilis},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.