Bacillus Clausii Spore has much advantage for our daily life
WHO define Probiotics as live microorganisms which, when administered in adequate amounts, confer a health benefit on the host . Probiotics in commercial product include Lactobacillus, Bifidobacterium, nonpathogenic strain of Escherichia coli (eg, E. coli Nissle 1917), Clostridium butyricum, Streptococcus salivarius, Saccharomyces boulardii and Bacillus.
A major probiotic product is Bacterial spore formers, mostly of the genus Bacillus.
Bacillus being ubiquitous consistently enter the gastrointestinal and respiratory tracts of healthy people. They have been isolated from gut and can reach upto 107 cfu/g  and hence are considered to be one of the dominant components of the normal gut microflora.
Bacillus clausii, a genus of Bacillus spp, is a gram–positive, aerobic, endospore–forming, facultative alkaliphilic rod bacterium, used as a human probiotic [5, 6].
Some advantages of Bacillus clausii product over the Lactobacillus products are:
+ Store indefinitely in a desiccated form  without any deleterious effect on viability
+ Survived the low pH of the gastric barrier .
The benefits of B. clausii, with recognized mechanism, are:
+ Prevention and treatment of acute intestinal infection ,
A Systematic Review and Meta-Analysis of Randomized Controlled Trials about Treatment of Acute Diarrhea in Children using Bacillus clausii (Gianluca Ianiro et al) indicate that Bacillus clausii combined with ORS might significantly reduce the duration of acute childhood diarrhea and the duration of hospital stay compared to ORS alone. Bacillus clausii might represent an effective therapeutic option in acute childhood diarrhea, with a good safety profile 
+ Prevention of side effects due to antibiotic therapy ,
A randomized, double-blind, placebo controlled trial about reducing side-effects of anti-Helicobacter pylori treatment by Bacillus clausii therapy was taken by Nista EC et al. The incidences of nausea, diarrhoea and epigastric pain in patients treated with B. clausii were significantly lower than in placebo group, in both PP and ITT analysis. Equally, intensity of nausea and diarrhoea in patients treated with B. clausii was significantly lower than in placebo group. There were no differences in adherence to treatment and H. pylori eradication rates between groups. B. clausii bacteriotherapy reduces the incidence of the most common side-effects related to anti-H. pylori antibiotic therapy. 
+ Stimulation of systemic immunoglobulin regulation, and in antimicrobial activity against Gram-positive bacteria [9, 10]
Gian Luigi Marseglia et al studied efficacy of Bacillus clausii spores in the prevention of recurrent respiratory infections in children. This pilot study provides the first preliminary evidence that B. clausii may exert a significant and persistent impact on respiratory infections in children and is safe and well tolerated.
B. clausii strains release antimicrobial substances in the medium. Moreover, the release of these antimicrobial substances was observed during stationary growth phase and coincided with sporulation. These substances were active against Gram-positive bacteria, in particular against Staphylococcus aureus, Enterococcus faecium, and Clostridium difficile. The antimicrobial activity was resistant to subtilisin, proteinase K, and chymotrypsin treatment, whereas it was sensitive to pronase treatment. The evaluation of the immunomodulatory properties of probiotic B. clausii strains was performed in vitro on Swiss and C57 Bl/6j murine cells. The science demonstrate that these strains, in their vegetative forms, are able to induce NOS II synthetase activity, IFN- production, and CD4+ T-cell proliferation. 
In addition, the ability of B. clausii spores to germinate in experimental conditions mimicking the gastrointestinal tract is consistent with the beneficial health effects reported for this spore–forming bacterium .
The latest evidence locating B. clausii species not only in the chicken gut but also in the human gut, proves that these spore-formers have the potential to persist in (or transiently associate with) the complex gut ecosystem .
 Joint F.A.O.WHO Working Group Report on Drafting Guidelines for the Evaluation of Probiotics in Food. Joint, F.A.O., London, Ontario, Canada(2002), p. 30
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 T.M. Barbosa, C.R. Serra, R.M. La Ragione, M.J. Woodward, A.O. Henriques. Screening for Bacillus isolates in the broiler gastrointestinal tract. Appl. Environ. Microbiol., 71 (2) (2005), pp. 968-978
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 Senesi S, Celandroni F, Tavanti A, Ghelardi E. Molecular characterization and identification of Bacillus clausii Strains marketed for use in oral bacteriotherapy. Appl Environ Microbiol. 2001 Feb; 67(2):834-9.
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. Duc le H, Hong HA, Barbosa TM, Henriques AO, Cutting SM . Characterization of Bacillus probiotics available for human use. Appl Environ Microbiol. 2004 Apr; 70(4):2161-71.
 Urdaci MC, Bressollier P, Pinchuk I. Bacillus clausii probiotic strains: antimicrobial and immunomodulatory activities. J Clin Gastroenterol. 2004 Jul; 38(6 Suppl):S86-90.
. Cenci G, Trotta F, Caldini G. Tolerance to challenges miming gastrointestinal transit by spores and vegetative cells of Bacillus clausii. J Appl Microbiol. 2006 Dec; 101(6):1208-15.
 Cenci G, Trotta F, Caldini G. Tolerance to challenges miming gastrointestinal transit by spores and vegetative cells of Bacillus clausii. J Appl Microbiol. 2006 Dec; 101(6):1208-15.
 Ianiro G, Rizzatti G, Plomer M, et al. Bacillus clausii for the Treatment of Acute Diarrhea in Children: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2018;10(8):1074. Published 2018 Aug 12. doi:10.3390/nu10081074
 Marseglia GL, Tosca M, Cirillo I, et al. Efficacy of Bacillus clausii spores in the prevention of recurrent respiratory infections in children: a pilot study. Ther Clin Risk Manag. 2007;3(1):13–17.
 E. C. Nista et al. Bacillus clausii therapy to reduce side‐effects of anti‐Helicobacter pylori treatment: randomized, double‐blind, placebo controlled trial. Aliment Pharmacol Ther. 2004 Nov 15;20(10):1181-8.
 Urdaci MC, Bressollier P, Pinchuk I. Bacillus clausii probiotic strains: Antimicrobial and immunomodulatory activities. J Clin Gastroenterol 2004;38 6 Suppl: S86-90. Back to cited text no.