Current Progress and Future Perspectives on the Use of Bacillus clausii

Water-insoluble dietary fiber from walnut relieves constipation through Limosilactobacillus reuteri-mediated serotonergic synapse and neuroactive ligand-receptor pathways

Dietary fiber can alleviate functional constipation (FC) by modulating the gut microbiota. To clarify the prebiotic properties of walnut insoluble dietary fiber (WIDF), we explored its structural characteristics and laxative mechanism. A galacturonic acid and glucose-rich WIDF was isolated from walnuts by using a complex enzymatic method. Animal experiments results showed that WIDF could effectively alleviate the symptoms of loperamide-induced FC in mice, including shortening the defecation time, increasing the wet weight and water content of feces, and promoting intestinal motility. WIDF might alleviate FC through activating serotonergic synapse and inhibiting the delta-opioid receptor/inducible nitric oxide synthase (Oprd/iNOS) pathways. Importantly, WIDF treatment altered the structure and composition of the gut microbiota. Correlation analysis revealed that Bacillus and its dominant ASV17, which is considered to be the key microbe for constipation alleviation, were strongly associated with constipation phenotypes. Based on pure culture and 16S rRNA gene phylogenetic analysis, Limosilactobacillus reuteri (L. reuteri), which is 100 % similar to ASV17, was isolated and identified from the feces of WIDF-treated mice. L. reuteri relieved FC by modulating serotonergic synapse and the Oprd/iNOS pathways. These results suggested that WIDF and L. reuteri treatment is a prospective strategy for the prevention of constipation.

16S rRNA metagenomic profiling of red amaranth grown organically with different composts and soils

In recent years organic food is gaining popularity as it is believed to promote better human health and improve soil sustainability, but there are apprehensions about pathogens in organic produces. This study was designed to understand the effect of different composts and soils on the status of the microbiome present in organically grown leafy vegetables. 16S rRNA metagenomic profiling of the leaves was done, and data were analyzed. It was found that by adding composts, the OTU of the microbiome in the organic produce was higher than in the conventional produce. The beneficial genera identified across the samples included plant growth promoters (Achromobacter, Paenibacillus, Pseudomonas, Sphingobacterium) and probiotics (Lactobacillus), which were higher in the organic produce. Some pathogenic genera, viz., plant pathogenic bacteria (Cellvibrio, Georgenia) and human pathogenic bacteria (Corynebacterium, Acinetobacter, Streptococcus, Streptomyces) were also found but with relatively low counts in the organic produce. Thus, the present study highlights that organic produce has lesser pathogen contamination than the conventional produce. KEY POINTS: • 16S rRNA metagenomics profiling done for organic red amaranth cultivar • Microbial richness varied with respect to the soil and compost type used • The ratio of beneficial to pathogenic genera improves with the addition of compost.

A Taguchi Approach for Optimization of Antimicrobial Effect of Whey Protein Based Edible Film Fermented by Bacillus clausii

Bacillus clausii, an antagonistic bacterium, was utilized to develop antimicrobial edible films based on whey protein concentrate. This study employed a Taguchi test (3 × 3) to evaluate the impact of temperature, pH, and protein concentration on film properties. Optimal growth of B. clausii occurred at 6% (w/v) protein and pH 9.5. The resulting film solutions demonstrated antimicrobial activity, exhibiting inhibition zones against Aspergillus niger, Penicillium expansum, Staphylococcus aureus, and Escherichia coli, with inhibition zone diameters of 13.68 mm, 16.88 mm, 11.38 mm, and 17.15 mm, respectively. The optimum antimicrobial property of the films was observed when the incubation condition of pH 8.5, 35 °C and 6% (w/v) protein. Survival rates of B. clausii in the dry film were 86% at 4 °C and 87% at 25 °C over 14 days. Additionally, the highest tensile strength (TS) and percent elongation at break (%E) for the films were recorded at 3.14 MPa (pH = 9.5, 37 °C, 8% protein) and 27.63% (pH = 9.0, 35 °C, 10% protein), respectively. These findings demonstrate the potential for developing effective antimicrobial films through 24-h fermentation of B. clausii in the film solution. This antimicrobial film shows potential for use in wound dressings or food packaging applications.

Comparative Evaluation of Spores and Vegetative Forms of Bacillus subtilis and Bacillus licheniformis on Probiotic Functionality In Vitro and In Vivo

The probiotic effects of Bacillus are strain-specific and dependent on both spore and vegetative forms, but the distinct contributions of these forms to probiotic functionality are not well understood. This study aimed to evaluate and compare the impacts of vegetative forms and spores of Bacillus subtilis and Bacillus licheniformis on probiotic functions in vitro and in vivo. We systematically assessed the anaerobic metabolic capabilities and the potential to enhance the intestinal barrier function of four Bacillus strains, leading to the selection of Bacillus subtilis X22 and Bacillus licheniformis N-3 for detailed investigation. Utilizing in vitro fermentation with murine fecal microbiota, we observed that the spores form of Bacillus licheniformis N-3 noticeably positively regulated the gut microbiota under anaerobic conditions. Concurrently, both spore and vegetative forms of Bacillus licheniformis N-3 and Bacillus subtilis X22 demonstrated the ability to prevent pathogen adhesion, reduce inflammation, combat oxidative stress, and promote cellular autophagy to reduce apoptosis in response to enterotoxigenic Escherichia coli (ETEC) infection in the IPEC-J2 cell model. As a facultative anaerobe, Bacillus licheniformis N-3 exhibited a tendency toward superior regulatory capacity in enhancing the anti-infective activity of IPEC-J2 cells in vitro. In the pathogens challenge mouse model, B. licheniformis N-3 effectively preserved the integrity of jejunal tissue and enhanced the expression of glycoproteins in goblet cells. Moreover, B. licheniformis N-3 strengthened the epithelial barrier by increasing the levels of Occludin and Claudin-1 in the jejunum, thus promoting overall intestinal health. This research offers new insights into strain selection and the life cycle utilization of Bacillus probiotics.

Randomized Clinical Trials Demonstrate the Safety Assessment of Alkalihalobacillus clausii AO1125 for Use as a Probiotic in Humans

(1) Background: Alkalihalobacillus clausii AO1125 is a Gram-positive, motile, spore-forming bacterium with potential as a probiotic due to its broad-spectrum antimicrobial activity, inhibiting pathogens like Listeria monocytogenes, Staphylococcus aureus, and Clostridium difficile, as well as anti-rotavirus activity. Its resilience in gastrointestinal conditions suggests benefits for gut health. This study evaluates the safety and probiotic potential of A. clausii AO1125. (2) Methods: Genome annotation identified genes linked to probiotic traits such as stress resistance, gut colonization, immune modulation, and antimicrobial production. The genome was screened for antibiotic resistance genes using CARD, bacteriocin clusters using BAGEL4, and virulence factors via VFDB. Cytotoxicity was assessed on Vero cells and erythrocytes, and a Phase I, double-blind, placebo-controlled clinical trial was conducted with 99 healthy volunteers (50 AO1125, 49 placebo). (3) Results: Genomic analysis confirmed minimal antibiotic resistance genes and the absence of virulence factors, supporting safety. A. clausii AO1125 showed no pathogenicity, cytotoxicity, or hemolytic activity and was well-tolerated in clinical settings, with mild, transient abdominal gas as the most common adverse event. (4) Conclusions: The safety profile and genetic basis for probiotic and antimicrobial properties support A. clausii AO1125 as a promising probiotic candidate for gastrointestinal health, warranting further clinical research.

Mycotoxin Biodegradation by Bacillus Bacteria-A Review

Mycotoxins are toxic secondary metabolites produced by various types of fungi that are known to contaminate various food products; their presence in the food chain poses significant risks to human and animal health and leads to enormous economic losses in the food and feed industry worldwide. Ensuring food safety and quality by detoxifying mycotoxin is therefore of paramount importance. Several procedures to control fungal toxins have been extensively investigated, such as preventive measures, physical and chemical methods, and biological strategies. In recent years, microbial degradation of mycotoxins has attracted much attention due to its reliability, efficiency, and cost-effectiveness. Notably, bacterial species from the Bacillus genus have emerged as promising candidates for mycotoxin decontamination owing to their diverse metabolic capabilities and resilience in harsh environmental conditions. This review manuscript aims to provide a summary of recent studies on the biodegradation of fungal toxins by Bacillus bacteria, thereby illustrating their potential applications in the development of mycotoxin-degrading products.

Protective role of cells and spores of Shouchella clausii SF174 against fructose-induced gut dysfunctions in small and large intestine

The oral administration of probiotics is nowadays recognized as a strategy to treat or prevent the consequences of unhealthy dietary habits. Here we analyze and compare the effects of the oral administration of vegetative cells or spores of Shouchella clausii SF174 in counteracting gut dysfunctions induced by 6 weeks of high fructose intake in a rat model. Gut microbiota composition, tight junction proteins, markers of inflammation and redox homeostasis were evaluated in ileum and colon in rats fed fructose rich diet and supplemented with cells or spores of Shouchella clausii SF174. Our results show that both spores and cells of SF174 were effective in preventing the fructose-induced metabolic damage to the gut, namely establishment of "leaky gut", inflammation and oxidative damage, thus preserving gut function. Our results also suggest that vegetative cells and germination-derived cells metabolize part of the ingested fructose at the ileum level.

Comparative Genomics and In Vitro Experiments Provide Insight into the Adaptation and Probiotic Properties of Shouchella clausii

Shouchella clausii (S. clausii) has been marketed as an important commercial probiotic, displaying significant therapeutic effects on antibiotic-associated diarrhea and providing benefits to humans. This study aimed to explore the distribution, adaptation, and probiotic properties of S. clausii. Based on 16S rRNA gene analysis, 43 strains of S. clausii were isolated from 317 soil samples in China. Based on the genomic index of Average Nucleotide Identity (ANI) results, 41 strains were confirmed as S. clausii, while two strains, FJAT-45399 and FJAT-45335, were identified as potential novel species distinct from S. clausii. Combined phenotypic and genomic predictions indicated that S. clausii could survive under harsh conditions. Comparative genomics revealed that these isolates possess antibiotic resistance genes, as well as capabilities for bacteriocin and folate production, while lacking toxins and hemolytic activity. Hemolysis tests indicated that strain FJAT-41761 exhibited non-pathogenic γ-hemolytic activity, while also demonstrating resistance to multiple antibiotics, consistent with probiotic characteristics. These findings suggest that strain FJAT-41761 is safe and holds potential as a future probiotic.

Bioactive compounds from food-grade Bacillus

Bacillus species have attracted significant attention in recent years due to their potential for producing various bioactive compounds with diverse functional properties. This review highlights bioactive substances from food-grade Bacillus strains and their applications in functional foods and nutraceuticals. The metabolic capacities of Bacillus species have allowed them to generate a wide range of bioactive substances, including vitamins, enzymes, anti-microbial peptides, and other non-ribosomal peptides. These substances have a variety of positive effects, including potential cholesterol-lowering and immune-modulatory qualities in addition to anti-oxidant and anti-bacterial actions. The uses and mechanisms of action of these bioactive chemicals can be used to improve the functional qualities and nutritional profile of food products. Examples include the use of anti-microbial peptides to increase safety and shelf life, as well as the use of Bacillus-derived enzymes in food processing to improve digestibility and sensory qualities. The exploitation of bioactive compounds from food-grade Bacillus strains presents a promising frontier in the development of functional foods and nutraceuticals with enhanced health benefits. Due to their wide range of activity and applications, they are considered as important resources for the development of novel medications, agricultural biocontrol agents, and industrial enzymes. Ongoing research into the biosynthetic pathways, functional properties, and applications of these compounds is essential to fully realize their potential in the food industry. This review underscores the significance of various bioactive compounds generated from Bacillus in tackling global issues like environmental sustainability, sustainable agriculture, and antibiotic resistance. Future developments in microbiology and biotechnology will enable us to fully utilize the potential of these amazing microbes, resulting in novel approaches to industry, agriculture, and health. © 2024 Society of Chemical Industry.

Oral toxicity evaluation of Bacillus clausii M31 isolated from the children's feces in the northern province of Vietnam

This study investigated the acute and repeated 28-day dose toxicity profiles of Bacillus clausii M31, isolated from children's feces, in Swiss rats and New Zealand rabbits. To investigate acute toxicity, rats were given varied doses of B. clausii M31 (1 × 1011 CFU/mL, 3 × 1011 CFU/mL, and 5 × 1011 CFU/mL) orally once daily for 14 days, in accordance with OECD recommendations No. 423. To evaluate toxicity, rabbits were given either a low dosage (1 × 1011 CFU/mL) or a high dose (5 × 1011 CFU/mL) during a 28-day period using the OECD Test Guideline 407 protocol. Neither death nor significant abnormalities were observed in the rats during the experiment. The microscopic examination of key organs revealed no substantial changes in organ morphology. Furthermore, analyses of serum biochemistry and hematological parameters did not reveal any treatment-associated variations. In sum, these findings suggest that the oral intake of B. clausii M31 at concentrations up to 5 × 1011 CFU/mL for 28 days poses no discernible risks.

The Role of Biotics as a Therapeutic Strategy for Oral Mucositis - A Systematic Review

OBJECTIVES

Oral mucositis (OM) is an acute and highly prevalent side effect of cancer treatments. Currently, there is no effective strategy for its prevention or treatment. This systematic review aimed to assess the effectiveness of biotics used as a therapeutic strategy for the management of OM.

MATERIALS AND METHODS

The PRISMA checklist was followed and PubMed, Web of Science, and Scopus were screened for clinical and pre-clinical studies assessing the potential effects of biotics in OM. Inclusion criteria included in vivo studies related to oral mucositis evaluating the effect of biotics, and written in Portuguese, English, French, Spanish, or Dutch. The following exclusion criteria were used: systematic reviews and meta-analyses, reviews, case reports, opinion papers or comments, conference papers, letters without results, articles not related to oral therapy-induced mucositis or biotics, or in vitro articles that do not simulate oral mucositis.

RESULTS

From a total of 1250 articles retrieved, 9 were included in this systematic review. Four clinical studies reported a reduction in oral mucositis occurrence with Lactobacillus species (Lactobacillus casei and Lactobacillus brevis CD2) and Bacillus clausii UBBC07. In pre-clinical studies, Lactococcus lactis genetically modified and Lactobacillus reuteri reduced the severity of OM and Streptococcus salivarius K12 also decreased the size of the ulcers.

CONCLUSION

The findings of this systematic review suggest that probiotic supplementation may potentially reduce the incidence of therapy-induced OM and decrease its severity in patients undergoing cancer treatment. However, the available evidence is marred by significant heterogeneity across studies.

Potential Complementary Effect of Zinc and Alkalihalobacillus clausii on Gut Health and Immunity: A Narrative Review

A balanced microbiota-microorganisms that live in the gut-is crucial in the early years of a child's life, while dysbiosis-altered microbiota-has been linked to the development of various diseases. Probiotics, such as Alkalihalobacillus clausii, are commonly used to restore the balance of gut microbiota and have shown additional antimicrobial and immunomodulatory properties. Intake of micronutrients can affect the structure and function of the gut barrier and of the microbiota by having multiple effects on cellular metabolism (e.g., immunomodulation, gene expression, and support structure proteins). An inadequate zinc intake increases the risk of deficiency and associated immune dysfunctions; it is responsible for an increased risk of developing gastrointestinal diseases, respiratory infections, and stunting. Paediatric zinc deficiency is a public health concern in many countries, especially in low-income areas. Currently, zinc supplementation is used to treat childhood diarrhoea. This review examines how combining A. clausii and zinc could improve dysbiosis, gut health, and immunity. It suggests that this combination could be used to prevent and treat infectious diseases and diarrhoea in children up to adolescence.

Probiotic characterization of Bacillus smithii: Research advances, concerns, and prospective trends

Bacillus smithii is a thermophilic Bacillus that can be isolated from white wine, hot spring soil, high-temperature compost, and coffee grounds, with various biofunctions and wide applications. It is resistant to both gastric acid and high temperature, which makes it easier to perform probiotic effects than traditional commercial probiotics, so it can maintain good vitality during food processing and has great application prospects. This paper starts with the taxonomy and genetics and focuses on aspects, including genetic transformation, functional enzyme production, waste utilization, and application in the field of food science as a potential probiotic. According to available studies during the past 30 years, we considered that B. smithii is a novel class of microorganisms with a wide range of functional enzymes such as hydrolytic enzymes and hydrolases, as well as resistance to pathogenic bacteria. It is available in waste degradation, organic fertilizer production, the feed and chemical industries, the pharmaceutical sector, and food fortification. Moreover, B. smithii has great potentials for applications in the food industry, as it presents high resistance to the technological processes that guarantee its health benefits. It is also necessary to systematically evaluate the safety, flavor, and texture of B. smithii and explore its biological mechanism of action, which is of great value for further application in multiple fields, especially in food and medicine.

A Prospective Real-World Study of Bacillus clausii Evaluating Use, Treatment Habits and Patient Satisfaction in Italian Community Pharmacies: The PEGASO Study

BACKGROUND

Ailments such as diarrhoea and antibiotic-associated gut symptoms are generally self-managed using probiotics. Real-world data on reasons behind self-medication with over-the-counter (OTC) products and patient-reported outcomes can be investigated strategically by the pharmacists.

OBJECTIVE

This study evaluates the use of Bacillus clausii (Enterogermina®) at the Italian community pharmacies among self-medicating patients, their treatment habits and perceived benefits.

DESIGN

This is a multicentre, prospective, non-interventional study which included two visits [at screening (T0) and end of the study (T1) when symptoms had subsided, ≤ 30 days from T0]. Patients who were already inclined to buy B. clausii were enrolled and instructed to complete a questionnaire at T0 and T1. The primary objective was to evaluate the reasons for taking B. clausii. Secondary objectives assessed treatment duration, perceived effectiveness, quality of life (QoL), treatment satisfaction and safety outcomes.

RESULTS

Overall, 268 patients were enrolled; 99.6% of them were evaluated at T0 and 97.4% at T1, and safety was evaluated in 97.8% who had ≥ 1 dose of B. clausii. At T0, mean age was 50.7 years and majority were females (62.2%). In the interview, main reason stated for using B. clausii at T0 was diarrhoea (56.93%), followed by other gastrointestinal symptoms. Treatment duration was shorter in those with diarrhoea or abdominal pain versus those with constipation or abdominal tension. More than 90% perceived their symptoms to have improved or improved very much. Overall QoL improved in all the aspects measured. Treatment satisfaction was reported by nearly 90% of patients as satisfied, very satisfied or extremely satisfied. No adverse events were reported.

CONCLUSION

This is the first pharmacy-based study in Italy that evaluated the real-world usage of an OTC probiotic containing B. clausii among self-medicating adults. Diarrhoea was the most common reason for use, with high-level of perceived effectiveness and patient satisfaction with B. clausii.

Microencapsulation and controlled release of Bacillus clausii through a novel non-digestible carbohydrate formulation as revolutionizing probiotic delivery

Probiotics have gained significant attention in recent years due to the growing awareness of physical health and well-being. However, maintaining high concentrations of probiotics throughout the product's shelf life and during the gastrointestinal tract is crucial for ensuring their health-promoting effects. After determining an optimal formulation through a fractional factorial model, this study optimizes probiotic Bacillus Clausii delivery through spray-drying microencapsulation using a novel maltodextrin-alginate-inulin (MDX-ALG-IN) formulation (optimized ratio: 7:2:1). Notably, this formulation exclusively comprises non-digestible carbohydrates, marking a novel approach in probiotic encapsulation. Achieving a high Product Yield (51.06 %) and Encapsulation Efficiency (80.53 %), the study employed SEM for morphological analysis, revealing an irregular form and extensive surface in dentations characteristic of maltodextrin involvement. With a low moisture content of 3.02 % (±0.23 %) and 90.52 % solubility, the powder displayed exceptional properties. Probiotic viability remained robust, surviving up to 60 % even after 180 days at 4 °C, 25 °C, and 37 °C. Thermal characterization unveiled microcapsule resilience, exhibiting a glass transition temperature (Tg) at 138.61 °C and a melting point of 177.28 °C. The study systematically addresses crucial aspects of microencapsulation, including formulation optimization, morphological characteristics, and powder properties. Notably, the MDX-ALG-IN microcapsules demonstrated stability in simulated gastrointestinal conditions, indicating potential application for supplements and complex food matrices. In summary, this research contributes to microencapsulation understanding, emphasizing the MDX-ALG-IN formulation's efficacy in preserving probiotic viability across production stages and simulated digestive processes.

Mechanistic Insight into the Role of Peptides Secreted from Bacillus clausii and Future Opportunities

Bacillus clausii is a commercial spore probiotic known to treat multiple diseases. An increased interest in exploring the nutraceutical and probiotic properties of various microorganisms has made researchers explore more about these bacteria. The current trends in the healthcare industry are majorly focused on devising new therapies to avoid drug and pathogen resistance in patients. Antimicrobial peptides have been considered a source of antibiotics for a long time. Still, getting new therapies into the market is a big challenge. Members of the genus Bacillus have been reported to have a broad spectrum of antimicrobial peptides. One of the least explored species under this genus is Bacillus clausii, concerning peptide drug therapy. The applications of Bacillus clausii in treating or preventing gut dysbiosis and respiratory infections have been largely supported in the past two decades. Yet research is lacking in explaining the pathways at molecular levels in targeting pathogens. In this mini-review, we are going to summarise the research that has been reported so far about peptide extraction from Bacillus clausii, their mode of action and advantages to mankind, and the challenges lying in the isolation of peptides.

Identification and characterisation of antimicrobial compound produced by probiotic Alkalihalobacillus clausii 088AE

In the present study, Alkalihalobacillus clausii 088AE was evaluated for the production of antimicrobial compounds, their characterisation, and identification. The results showed that, 48-h-old A. clausii supernatant is able to inhibit the growth of indicator bacteria Micrococcus luteus MTCC 106T (7.0 ± 0.51 mm). The cultivation of 088AE on solid media along with XAD16N beads for 5 days, and isopropanol extraction of antimicrobial compound thereof showed enhanced antimicrobial activity (19.67 ± 0.58 mm) against indicator strain. Further purification with a reversed-phase C18 cartridge yielded a powder with 389.12 ± 10.08 μg of protein per mg. The UV spectra of the sample revealed the characteristic aromatic amino acid peaks at 262 and 276 nm. The results of triple-quadrupole mass spectrometry showed a peak of 1055 m/z, confirming the existence of 10542+, i.e., 2108 Da, suggestive of class I lantibiotic clausin. Furthermore, in silico analysis confirmed the presence of genes responsible for the production of lanthipeptide clausin. The clausin is stable in the presence of proteases (trypsin and pepsin), high temperature (100 °C), pH up to 11 and showed antimicrobial activity against Listeria monocytogenes ATCC 19115, M. luteus, and Staphylococcus aureus ATCC 6538P. Therefore, it could be useful to control gut infections caused by Gram-positive pathogens.

Genetic and phenotypic assessments for the safety of probiotic Bacillus clausii 088AE

In this study, we report on whole genome sequence analysis of clinically documented, commercial probiotic Bacillus clausii 088AE and genome features contributing to probiotic properties. The whole genome sequence of B. clausii 088AE generated a single scaffold of 4,598,457 bp with 44.74 mol% G + C. This assembled genome sequence annotated by the RAST resulted in 4371 coding genes, 75 tRNAs, and 22 rRNAs. Gene ontology classification indicated 39.5% proteins with molecular function, 44.24% cellular component, and 16.25% proteins involved in biological processes. In taxonomic analysis, B. clausii 088AE shared 99% identity with B. clausii DSM 8716. The gene sequences related to safety and genome stability such as antibiotic resistance (840), virulence factors (706), biogenic amines (1), enterotoxin (0), emetic toxin (0), lanthipeptides (4), prophage (4) and clustered regularly interspaced short palindromic repeats (CRISPR) sequences (11), were identified and evaluated for safety and functions. The absence of functional prophage sequences and the presence of CRISPR indicated an advantage in genome stability. Moreover, the presence of genome features contributing to probiotic characteristics such as acid, and bile salt tolerance, adhesion to the gut mucosa, and environmental resistance ensure the strains survivability when consumed as a probiotic. In conclusion, the absence of risks associated with sequences/genes in the B. clausii 088AE genome and the presence of essential probiotic traits confirm the strain to be safe for use as a probiotic.

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.

In Vitro Evaluation of Antiviral Activity Effect of Selenium, Bacillus clausii Supernatant, and Their Combination on the Replication of Herpes Simplex Virus 1

Background: About 70% of individuals worldwide suffer from herpes simplex virus 1 (HSV-1). Several studies have reported that selenium and supernatant of probiotic bacteria are antiviral; nevertheless, their effect alone or synergistically on HSV-1 is unknown. Objectives: The present study aimed to evaluate the antiviral effects of Bacillus clausii supernatant, selenium (Se), and their combination on HSV-1. Methods: After determining cytotoxicity by the MTT assay, selenium and B. clausii supernatants were added to HeLa cells 24 hours before (pre-infection treatment) and after (post-infection treatment) HSV-1 inoculation. After 47 hours of incubation at 37°C, the viral titer and expression levels of the unique long 47 (UL47) gene were determined by the 50% tissue culture infectious dose (TCID50) and real-time polymerase chain reaction methods, respectively. Results: The bacterial supernatant in dilutions of 1:4 and 1:8, selenium in concentrations of 0.5 and 1 μM, and a combination of them had a cytotoxicity level lower than 80% in HeLa cells. The HSV-1 titers in pre-infection and post-infection assays with a dilution of 1:4 supernatant decreased by about 2.16 and 1 log10 TCID50/mL, respectively. Moreover, 1 μM Se could reduce the virus titer by 2.33 log10 TCID50/mL. The virus titer showed a greater decrease when Se and the bacterial supernatants were combined than when only one of the two was used. The highest selectivity index (SI) was obtained when selenium and bacterial supernatant were combined (SI = 29.2). The combined use of 1 μM Se and a 1:4 dilution of B. clausii supernatant caused the greatest drop in virus titer (3.3 log10 TCID50/mL) in comparison to other treatment conditions. The UL47 gene expression was reduced by Se at concentrations of 0.5 and 1 μM by about 1.6- and 2-fold, respectively. The UL47 expression showed a higher decline when selenium and bacterial supernatant were combined than when only one of the two was employed, which is similar to viral titer data. Conclusions: Selenium and the supernatant of B. clausii have potent antiviral activity against HSV-1. The combination of selenium and the bacterial supernatant has a synergistic effect in reducing HSV-1 replication. However, further research is required to fully understand how they inhibit viruses.

Bacillus-derived probiotics: metabolites and mechanisms involved in bacteria-host interactions

Bacillus probiotics have a sporulation capacity that makes them more suitable for processing and storage and for surviving passage through the gastrointestinal tract. The probiotic functions and regulatory mechanisms of different Bacillus have been exploited in many reports, but little is known about how various Bacillus probiotics perform different functions. This knowledge gap results in a lack of specificity in the selection and application of Bacillus. The probiotic properties are strain-specific and cell-type-specific, and are related to the germination potential and to the diversity of metabolites produced following intestinal germination, as this causes the variation in probiotic function and mechanisms. In this review, we discuss the Bacillus metabolites produced during germination and sporulation in the GI tract, as well as possible processes affecting intestinal homeostasis. We conclude that the oxygen-capturing capability and the production of antimicrobials, exoenzymes, competence and sporulation factors (CSF), exopolysaccharides, lactic acid, and cell components are specifically associated with the functional mechanisms of probiotic Bacillus. The aim of this review is to guide the screening of potential Bacillus strains for probiotics and their application in nutrition research. The information provided will also promote further research on Bacillus-derived functional metabolites in human nutrition.