Alkalihalobacillus clausii (formerly Bacillus clausii) spores lessen antibiotic-induced intestinal injury and reshape gut microbiota composition in mice.

The antibiotic-induced intestinal injury (AIJ) is associated with diarrhoea and gastrointestinal discomfort. However, the pathological intestinal mechanisms and related side effects associated with antibiotic use/misuse may be counteracted by probiotics. This study aims to evaluate the effect and the protective mechanisms of a probiotic formulation containing Alkalihalobacillus clausii (formerly Bacillus clausii; BC) spores in an experimental model of AIJ. C57/Bl6J mice were orally challenged with a high dose of ceftriaxone for five days along with BC treatment which lasted up to the 15th day. Our results showed the beneficial effect of the probiotic in preserving colonic integrity and limiting tissue inflammation and immune cell infiltration in AIJ mice. BC increased tight junction expression and regulated the unbalanced production of colonic pro- and anti-inflammatory cytokines, converging toward the full resolution of the intestinal damage. These findings were supported by the histological evaluation of the intestinal mucosa, suggesting a potential restoration of mucus production. Notably, BC treatment increased gene transcription of the secretory products responsible for epithelium repair and mucus synthesis and normalized the expression of antimicrobial peptides involved in immune activation. Reconstruction of complex and diverse gut microbiota in antibiotic-induced dysbiosis was recorded upon BC supplementation. Specifically, the expansion of A. clausii, Prevotella rara and Eubacterium ruminatium drove intestinal microbiota rebalance by primarily impacting Bacteroidota members. Taken together, our data indicate that BC administration alleviates AIJ by multiple converging mechanisms leading to restoring gut integrity and homeostasis and reshaping microbiota composition.

Gut immune homeostasis: the immunomodulatory role of Bacillus clausii, from basic to clinical evidence.

INTRODUCTION: The gut microbiota affects the development of the gut immune system in early life. Perturbations to microbiota structure and composition during this period can have long-term consequences on the health of the individual, through its effects on the immune system. Research in the last few decades has shown that probiotic administration can reverse these effects in strain- and environment-specific ways. Bacillus clausii (B. clausii) has been in use for many decades as a safe and efficacious probiotic, but its mode of action has not yet been completely elucidated. AREAS COVERED: In this review, we discuss how the gut immune system works, the factors that affect its functioning, and the plethora of research highlighting its role in various diseases. We also discuss the known modes of action of Bacillus probiotics, and highlight the preclinical and clinical evidence that reveal how B. clausii acts to bolster gut defense. EXPERT OPINION: We anticipate that the treatment and/or prevention of dysbiosis will be central to managing human health and disease in the future. Discovering the pathophysiology of autoimmune diseases, infections, allergies, and some cancers will aid our understanding of the key role played by microbial communities in these diseases.

Probiotics L. acidophilus and B. clausii Modulate Gut Microbiota in Th1- and Th2-Biased Mice to Ameliorate Salmonella Typhimurium-Induced Diarrhea.

Gut microbiota play important role in maintaining health. Probiotics are believed to augment it further. We aimed at comparing effects of probiotics, Lactobacillus acidophilus (LA) and Bacillus clausii (BC) (a) on the gut microbiota abundance and diversity and (b) their contributions to control intestinal dysbiosis and inflammation in Th1- and Th2-biased mice following Salmonella infection. We report how could gut microbiota and the differential immune bias (Th1 or Th2) of the host regulate host responses when challenged with Salmonella typhimurium in the presence and absence of either of the probiotics. LA was found to be effective in ameliorating the microbial dysbiosis and inflammation caused by Salmonella infection, in Th1 (C57BL/6) and Th2 (BALB/c)-biased mouse. BC was able to ameliorate Salmonella-induced dysbiosis and inflammation in Th2 but not in Th1-biased mouse. These results may support probiotics LA as a treatment option in the case of Salmonella infection.

Composite genome sequence of Bacillus clausii, a probiotic commercially available as Enterogermina®, and insights into its probiotic properties.

BACKGROUND: Some of the spore-forming strains of Bacillus probiotics are marketed commercially as they survive harsh gastrointestinal conditions and bestow health benefits to the host. RESULTS: We report the composite genome of Bacillus clausii ENTPro from a commercially available probiotic Enterogermina® and compare it with the genomes of other Bacillus probiotics. We find that the members of B. clausii species harbor high heterogeneity at the species as well as genus level. The genes conferring resistance to chloramphenicol, streptomycin, rifampicin, and tetracycline in the B. clausii ENTPro strain could be identified. The genes coding for the bacteriocin gallidermin, which prevents biofilm formation in the pathogens Staphylococcus aureus and S. epidermidis, were also identified. KEGG Pathway analysis suggested that the folate biosynthesis pathway, which depicts one of the important roles of probiotics in the host, is conserved completely in B. subtilis and minimally in B. clausii and other probiotics. CONCLUSIONS: We identified various antibiotic resistance, bacteriocins, stress-related, and adhesion-related domains, and industrially-relevant pathways, in the genomes of these probiotic bacteria that are likely to help them survive in the harsh gastrointestinal tract, facilitating adhesion to host epithelial cells, persistence during antibiotic treatment and combating bacterial infections.

Use of whey as a culture medium for Bacillus clausii for the production of protein hydrolysates with antimicrobial and antioxidant activity.

The use of whey as a natural culture medium to produce hydrolysates with antimicrobial from Bacillus clausii is the objective of this research. The fermentation process was carried out at 25 ℃ for five days, where proteolytic activity, soluble peptides quantification, and antimicrobial activity using the disc diffusion method were determined every day. The fermented whey reached values ​​of proteolytic activity between 90 and 260 U ml-1 and a production of soluble peptides between 100 and 2070 µg ml-1. The maximum values ​​were reached after three days of fermentation to all determinations. In addition, the inhibition zone of fermented whey against Salmonella Typhimurium, Escherichia coli, Shigella flexneri, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis strains were 13.7, 13.2, 14.4, 14.6, 9.8, 15.7 mm, respectively. The hydrolysates inhibited the 2, 2'-azinobis (3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals by 85 and 80%, respectively. The whey was used to allow the growth of B. clausii and to generate peptides with antioxidant and antimicrobial activity through the hydrolysis of proteins present in the natural culture medium. This process could be used for the development of new dairy products added with probiotics.

Bacillus clausii and gut homeostasis: state of the art and future perspectives.

INTRODUCTION: The intestinal barrier is a complex system responsible for the host health. Many gastrointestinal and extra-intestinal diseases are associated to gut barrier disruption. An increasing interest on nutritional supplements and functional foods focused on the hypothesis that specific prebiotics and probiotics may modulate and interact with gut barrier, re-establishing gut homeostasis. AREAS COVERED: The application of preparations containing B. clausii in the treatment or prevention of gut phisiology impairment has been largely supported in the last years and has driven its clinical applications. This review focuses on B. clausii clinical applications and speculates on the possible interactions among B. clausii, gut barrier and immune system and on the consequences of this interplay in modulating human health. Expert commentary: Its favorable effects have been linked to several properties, such as antimicrobial and immunomodulatory activity, regulation of cell growth and differentiation, cell-cell signaling, cell adhesion, signal transcription and transduction, production of vitamins and gut protection from genotoxic agents. In this scenario, future studies will need to better clarify its mechanisms of action and focus on the possible role of B. clausii in modulating gut immune system.