Entry 27
Probiotic science page
Uses spore germination in the small intestine and bile salt hydrolase activity to improve blood lipids and gut barrier function, with RCT evidence.
Overview
Bacillus subtilis DE111 is a probiotic strain that forms spores (tough survival shells). BIO-CAT (Troy, Virginia, USA) markets it for dietary supplementation [1]. Researchers characterized the strain in lab tests and in silico for probiotic properties. It demonstrated antimicrobial activity, bile tolerance, and spore germination capacity in the human GI tract [1]. Human RCTs have evaluated DE111 for gastrointestinal health, blood lipid modulation, endothelial function, and exercise recovery [2,3,4,5,6].
Mechanism
B. subtilis DE111 produces endospores. These survive gastric acid and bile exposure. They germinate in the small intestinal lumen to yield metabolically active vegetative cells [2]. The strain secretes antimicrobial substances. These include subtilin-like bacteriocins and lipopeptides (surfactin, iturin). They inhibit Gram-positive pathogens [1]. Lab tests and in silico analysis confirmed DE111’s capacity for bile salt hydrolase activity. They confirmed it sticks to cells lining the gut. They also confirmed production of digestive enzymes (protease, amylase, cellulase) [1]. Following oral ingestion, DE111 spores germinate within the human small intestine. A crossover RCT demonstrated this by recovering vegetative cells from duodenal aspirates [2]. In mice fed a Western diet, DE111 partially reversed endothelial dysfunction. It reduced vascular oxidative stress and improved nitric oxide bioavailability [6] (animal). The mechanism of lipid improvement may involve modulation of bile acid metabolism and short-chain fatty acid production [4].
Health Benefits
A randomized, double-blind, placebo-controlled crossover study enrolled healthy adults. It demonstrated that DE111 spores germinate in the human small intestinal tract. This confirmed viability in the body and gastrointestinal transit [2] (RCT). A double-blind RCT enrolled 44 healthy adults. It showed that DE111 supplementation for 4 weeks improved blood lipid profiles. It reduced total cholesterol and non-HDL cholesterol. It also improved endothelial function [4] (RCT). A separate RCT enrolled healthy adults. It found that DE111 modulated gastrointestinal symptoms and immunological markers. Anti-inflammatory cytokines increased [3] (RCT). In 28 children attending day-care, daily DE111 intake supported a healthy gut microbiome. It reduced potentially pathogenic populations [5] (observational/intervention). In mice fed a Western diet, DE111 partially reversed endothelial dysfunction and vascular oxidative stress [6] (animal). In 15 active men and women, 28 days of DE111 supplementation did not significantly alter plasma amino acid response to whey protein ingestion [7]. Evidence quality is limited by small sample sizes and heterogeneous endpoints.
Biology
Bacillus subtilis is a Gram-positive rod. It grows with or without oxygen. It forms endospores. It measures approximately 0.7-0.8 × 2.0-3.0 µm. It belongs to the family Bacillaceae within the phylum Bacillota [1]. DE111 produces ellipsoidal to cylindrical endospores located subterminally. These confer resistance to heat (surviving >80°C), desiccation, UV radiation, and gastric acidity [1]. Its metabolism is facultative. B. subtilis can grow aerobically (catalase-positive) and fermentatively. It produces acetoin, 2,3-butanediol, and organic acids from glucose [1]. B. subtilis is motile by peritrichous flagella. It forms rough, wrinkled colonies on agar [1]. Natural habitat includes soil, the rhizosphere, and plant surfaces. There it contributes to nutrient cycling and biocontrol of plant pathogens [1]. Whole-genome sequencing and comparative genomics confirmed the DE111 strain as B. subtilis [1].
Bibliography
Mazhar S, Khokhlova E, Colom J, et al. (2023). In vitro and in silico assessment of probiotic and functional properties of Bacillus subtilis DE111. Frontiers in Microbiology. 13:1101144. PMID: 36713219
Colom J, Freitas D, Simon A, et al. (2021). Presence and germination of the probiotic Bacillus subtilis DE111 in the human small intestinal tract: a randomized, crossover, double-blind, and placebo-controlled study. Frontiers in Microbiology. 12:715863. PMID: 34408741
Freedman KE, Hill JL, Wei Y, et al. (2021). Examining the gastrointestinal and immunomodulatory effects of the novel probiotic Bacillus subtilis DE111. International Journal of Molecular Sciences. 22(5):2453. PMID: 33671071
Trotter RE, Vazquez AR, Grubb DS, et al. (2020). Bacillus subtilis DE111 intake may improve blood lipids and endothelial function in healthy adults. Beneficial Microbes. 11(7):621-630. PMID: 33161737
Paytuví-Gallart A, Sanseverino W, Winger AM. (2020). Daily intake of probiotic strain Bacillus subtilis DE111 supports a healthy microbiome in children attending day-care. Beneficial Microbes. 11(7):611-620. PMID: 33161736
Risk BD, Graham EL, Zhang M, et al. (2024). Bacillus subtilis DE111 partially reverses endothelial dysfunction in western-diet fed mice. Beneficial Microbes. 16(3):311-327. PMID: 39631408
Townsend JR, Vantrease WC, Jones MD, et al. (2020). “Plasma Amino Acid Response to Whey Protein Ingestion Following 28 Days of Probiotic (Bacillus subtilis DE111) Supplementation in Active Men and Women.” J Funct Morphol Kinesiol. 5(4):90. PMID: 33462163
Available Products
BIO-CAT Inc. (Troy, Virginia, USA) supplies Bacillus subtilis DE111 as a spore-based probiotic ingredient for dietary supplements [1]. The product is available in capsule, powder, and tablet formats. It is also incorporated into functional foods and beverages due to spore thermal stability. Typical daily dose in clinical studies is approximately 1 × 10^9 to 5 × 10^9 CFU (colony-forming units, a live bacteria count) [2,3,4].