B. subtilis is a probiotic with antioxidant properties and with beneficial effects on the GI tract and the immune system.

What is Bacillus subtilis?

Bacillus subtilis is a spore creating Gram-positive bacterium, found in soil and the gastrointestinal tract of ruminants, such as cattle, goats, and sheep. It is also found in the human GI tract.

Bacillus subtilis can survive in harsh environmental conditions. Its spores can survive up to 6 years in space if coated by dust particles protecting it from solar UV rays [1].

This bacterium is widely used on an industrial scale by biotechnology companies, for the production of enzymes, pharmaceutical components, and GMOs. As a human probiotic, however, Bacillus subtilis has been somewhat neglected.

Bacillus subtilis cultures were popular worldwide before the introduction of antibiotics when Bacillus subtilis was used as an immunostimulatory agent to aid the treatment of gastrointestinal and urinary tract diseases. After the 1950s, with the introduction of antibiotics, this probiotic declined in popularity.

On the other hand, Bacillus subtilis has been extensively used in the livestock and poultry industries as antibiotic alternatives [2].

Bacillus subtilis is used in the commercial production of the Japanese food natto, as well as the similar Korean food cheonggukjang. Furthermore, a formulation containing a combination of Enterococcus faecium and Bacillus subtilis has been available and widely used in Asia since 1994 [3].

Health Benefits

1) Has Antioxidant Properties

B. subtilis has DNA protective and antioxidant (superoxide scavenging) activity [4].

A B. subtilis signal molecule induces the heat shock protein Hsp27 in mammalian cells, which protects intestinal cells against oxidant-mediated tissue damage and loss of barrier function [5].

2) May Be Beneficial in Obesity

B. subtilis decreases weight gain and alleviates oxidative stress in obese mice [6].

3) May be Beneficial in Diabetes

Diabetic patients who develop foot ulcers are at more risk of dying prematurely than those without the complication. B. subtilis shows antimicrobial activity against four diabetic foot ulcer bacterial pathogens [7].

4) Is Beneficial for the GI Tract

B. subtilis Beneficially Modifies Gut Microbiota

Ingestion of significant quantities of B. subtilis spores is thought to restore the normal gut microbiota in humans following extensive antibiotic usage or illness [2].

B. subtilis increases Bifidobacteria, decreases some Clostridium groups [8], and enhances the growth of L. reuteri and L. acidophilus in laboratory experiments [9].

B. subtilis Relieves Constipation

A combined regimen of lactulose and live binary B. subtilis is an effective and safe therapeutic method for elderly with functional constipation [10].

B. subtilis Ameliorates Diarrhea

B. subtilis significantly reduced the incidence of antibiotic-associated diarrhea in patients, and prevented nausea, bloating, vomiting and abdominal pain [11].

In one of the Asian clinical trials, a mixture of E. faecium and B. subtilis improved abdominal pain, distention, and fever in patients with acute diarrhea. However, most of the trials did not find a significant difference with these probiotics in acute diarrhea treatment [3].

Results were more encouraging in chronic diarrhea patients, where a significant increase in Bifidobacteria levels following therapy was observed. Treatments also prevented diarrhea relapse [3].

B. subtilis May be Beneficial in IBS

B. subtilis together with E. faecium significantly reduced the severity and frequency of abdominal pain in patients with Irritable Bowel Syndrome (IBS) in a single Asian clinical trial, however other results are not as convincing, and further studies are needed [3].

B. subtilis is Beneficial in IBD

In Asian studies involving patients with ulcerative colitis, the addition of a B. subtilis probiotic significantly reduced the number of days with bloody stool, led to complete remission without relapse, and significantly increased the efficacy of mesalazine or sulfasalazine therapy [3].

A higher dose of B. subtilisis administration ameliorated dysbiosis and gut inflammation by balancing beneficial and harmful bacteria and associated anti- and pro-inflammatory cytokines in mice [12].

B. subtilis and its competence and sporulation factor (CSF) ameliorate intestinal inflammation and improve survival in mice with colitis [13, 14].

B. subtilis reduces inflammation and suppresses colitis in rats [15].

5) Is Beneficial in H. pylori therapy

B. subtilis containing probiotics improved H. pylori eradication and decreased diarrhea and total side effects when used in conjunction with triple therapy [3].

6) Boosts Immunity

B. subtilis spores stimulate the immune response when co-administered with a vaccine for papillomavirus type 16 (HPV-16) in mice [16].

B. subtilis both can instruct a balanced Th1 and Th2 immune response to specific antigens in mice [17].

Intravenous injection of B. subtilis in mice induces plasma IFN-y production [18].

7) Combats Infections

Bacteriocin of B. subtilis was shown to inhibit the growth of various pathogenic bacteria [19] and decrease the frequency of respiratory infections in elderly subjects [20].

B. subtilis inhibits disease transmission in patients with acute non-typhoid Salmonella gastroenteritis [21].

B. subtilis isolated from soil shows antimicrobial activity against human pathogenic Candida albicans [22].

Metabolites of B. subtilis decrease the resistance of urogenital pathogenic microflora to antibiotics in patients with urinary tract infections, resulting in accelerated elimination [23].

Spores of B. subtilis attenuate the symptoms of Clostridium difficile infection in mice [24].

B. subtilis suppresses infection and enteropathy in suckling mice infected with C. rodentium [25].

8) May be Beneficial in Liver Disorders

B. faecium and B. subtilis shift the intestinal microbiota of patients with liver cirrhosis back towards levels observed in healthy subjects. These probiotics also reduce circulating endotoxin levels in cirrhotic patients with endotoxemia [3].

9) May Benefit the Skin

Continuous oral administration of B. subtilis alleviates the development of skin lesions in mice with atopic dermatitis [26].

10) May be Beneficial for Dental Health

Bacillus subtilis reduces periodontal pathogens in humans [27].

Bacillus subtilis and Bacillus licheniformis supplementation provided a protective effect against bone loss in rats with periodontitis [28].

11) May Alleviates Heat Stress

Exposure to extreme heat can cause illnesses and injuries. Bacillus. subtilis was effective in the prevention of complications related to heat stress in rats. When rats were subjected to heat stress (45 °C), adverse effects such as morphological changes in the intestine, bacterial translocation, elevated levels of LPS and IL-10, and increased vesiculation of erythrocytes were observed only in animals not protected with B. subtilis [29].

12) May Combat Cancer

Components of Bacillus subtilis inhibit colon cancer cell growth [30, 31], hepatocellular cancer cell growth [32], cervix carcinoma cell growth [33], and the growth of human leukemia cells [34] in laboratory experiments.


  • Increases IL-8, IL-12 [35] and TGF-β [15]
  • Mostly increases IL-10 [14, 13, 15] (a study where IL-10 is decreased: [35]
  • Increases IgA [20, 17] and IgG [17]
  • Decreases IL-4 [13], CXCL-1 [13]
  • Both decreases [13, 15] and increases IL-6 [35]
  • Both decreases [15] and increases TNF-α [35]
  • Both decreases [15] and increases IL-1β [35]
  • Both decreases [15] and increases IFN-γ [35]
  • Increases ACP, LDH, NO, and iNOS [35]
  • Decreases glutathione reductase (GR), xanthine oxidase (XO), heat-shock protein 90 (Hsp90), and lipid synthesis gene 3β-hydroxysteroid-∆24 reductase (DHCR24) [6]


Bacillus subtilis is safe and well tolerated by healthy adults [36, 37]. However, its use in rare cases can lead to bacteremia (infection) [38], hepatotoxicity [39] and heavy exposure to spores can cause allergic asthma [40].


A probiotic product containing B. subtilis:

  • Probiotics (prescript assist) – great for IBS

This section contains sponsored links, which means that we may receive a small percentage of profit from your purchase, while the price remains the same to you. The proceeds from your purchase support our research and work. Thank you for your support.

About the Author

Biljana Novkovic - PHD (ECOLOGICAL GENETICS) - Writer at Selfhacked

Dr. Biljana Novkovic, PhD

PhD (Ecological Genetics)

Biljana received her PhD from Hokkaido University.

Before joining SelfHacked, she was a research scientist with extensive field and laboratory experience. She spent 4 years reviewing the scientific literature on supplements, lab tests and other areas of health sciences. She is passionate about releasing the most accurate science & health information available on topics, and she's meticulous when writing and reviewing articles to make sure the science is sound. She believes that SelfHacked has the best science that is also layperson-friendly on the web.

Click here to subscribe


1 Star2 Stars3 Stars4 Stars5 Stars
(16 votes, average: 4.38 out of 5)

FDA Compliance

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.