Brevibacillus

Brevibacillus: A Comprehensive Reference Article

1. Identity, Nomenclature, and Taxonomy

Brevibacillus is a genus of Gram-positive, spore-forming bacteria that has emerged as a promising ingredient in nutritional and probiotic products. The genus name derives etymological roots in Latin: the genus name Brevibacillus derives from the Latin adjective brevis (short) combined with the masculine noun bacillus (a small rod), referring to the short rod-shaped cells characteristic of the organisms within this genus.

In 1900, for the very first time, Bacillus brevis was described by Migula. During the 1900s, many other strains were classified as Bacillus brevis on the basis of similar phenotypic characteristics. Consequently, Bacillus brevis became a heterogeneous species. After subsequent studies on B. brevis and related strains, reclassification was done as novel species of the genera Brevibacillus and Aneurinibacillus on the basis of polyphasic taxonomy. The genus Brevibacillus was formally proposed on the basis of the description of 10 species related to the Brevibacillus brevis type strain in 1996. Specifically, in 1996, Osamu Shida and colleagues reclassified Bacillus brevis into the newly proposed genus Brevibacillus based on phylogenetic analysis of 16S rRNA gene sequences, which revealed distinct clustering from other Bacillus species.

The formal taxonomic standing of the genus is well-established. The type species is Brevibacillus brevis (Migula 1900) Shida, Takagi, Kadowaki and Komagata 1996. LPSN classification places the genus within the hierarchy: Bacteria / Bacillati / Bacillota / Bacilli / Caryophanales / Paenibacillaceae / Brevibacillus. The genus is classified from Bacillus based on 16S rRNA sequence analysis.

Species-level differentiation within Brevibacillus relies on a range of biochemical characteristics. Biochemical characterization that can aid in the differentiation at the species level is limited. Species are classified mainly on ability to produce enzymes such as catalase and oxidase. Nitrate-reducing capability has some significance to distinguish species. The ability of the organisms to hydrolyze casein, starch, gelatin, Tween 80, urea, and deoxyribonucleic acid is of value to differentiate Brevibacillus at the species level.

Among the most scientifically and commercially studied species within the genus are Brevibacillus brevis and Brevibacillus laterosporus. Brevibacillus brevis (formerly known as Bacillus brevis) is a Gram-positive, aerobic, motile, spore-forming, rod-shaped bacterium commonly found in soil, air, water, and decaying matter. Brevibacillus laterosporus is a Gram-positive bacterium that produces spores in nature; it is found in soil, fresh water, sea water, insect bodies, and plant surfaces. B. laterosporus is further distinguished by a characteristic canoe-shaped parasporal crystal structure, and is a rod-shaped, endospore-forming bacterium with a distinctive canoe-shaped parasporal crystal, commonly used as a probiotic for biological control.

1.1 Natural Sources and Ecological Distribution

Members of the genus are widely spread in nature. They can be found in a variety of environments including intestinal tracts of animals, seawater, and soil. B. laterosporus is widely distributed and can be found in a variety of ecosystems, including soil, water, and animal bodies. Precisely because of its wide range of sources, researchers have obtained strains with different characteristics from different places such as the rhizosphere of plants, seawater, and animal digestive systems. Brevibacillus brevis thrives in terrestrial environments, particularly in soil, where it generates gramicidin as an antimicrobial peptide to disrupt the cell membranes of competing Gram-positive bacteria, thereby facilitating its ecological niche.

Certain strains have also been isolated from distinctly niche environments: B. laterosporus is an indigenous microorganism found in the gastrointestinal tract of various insects, including bees. It has the beneficial effects to improve bee gut microbiota, increase the population of worker bees and larvae, and boost the production of pollen and honey.

1.2 Common Forms and Preparations

Brevibacillus species have been recognized for their robust ability to survive harsh environmental conditions, owing to their spore-forming nature. This resilience has positioned them as potential candidates for use in food and dietary supplements, especially where stability and survivability through the gastrointestinal tract are important.

In research and commercial contexts, Brevibacillus laterosporus has been evaluated in several forms. Studies have investigated the effects of dietary Brevibacillus laterosporus BL1 in both live and heat-killed forms. Preparations used in animal feeding studies have taken the form of spray-dried powdered microbial agents: the strain was fermented in a high-yield optimized medium for 48 h and subsequently spray-dried into a powdered microbial agent containing B. laterosporus at a concentration of 5 × 10¹⁰ CFU/g. Some Brevibacillus strains have been used commercially as probiotics.

2. Historical and Traditional Context

As a genus that was formally characterized only in the late 20th century, Brevibacillus does not carry documented traditional use under its current taxonomic name. While specific documentation of Brevibacillus use in traditional medicine is limited, related Bacillus species have long played a role in fermented foods and natural remedies across diverse cultures. The most historically significant development for the genus concerns the isolation of its bioactive compounds in the early antibiotic era.

It was independently discovered at the end of the 1930s and the beginning of the 1940s that various strains of the soil bacterium Brevibacillus brevis (formerly Bacillus brevis) produced substances inhibiting a range of pathogenic bacteria and even fungi. This species appeared to be producing a variety of linear and cyclic peptides using nonribosomal protein synthetases.

The pivotal discovery was made by microbiologist René Dubos. He used a selective enrichment method for a new search for an agent to combat bacterial infections, this time feeding soil a mixture of Gram-positive bacteria. His samples yielded a bacterium called Bacillus brevis, which secreted two substances that killed or inhibited Gram-positive bacteria. Tyrothricin, isolated by René Dubos in 1939, appeared to be a mix of cyclic and linear polypeptides with antimicrobial activity. Its principal component is tyrocidine, which is also a mixture of cyclic decapeptides. Gramicidin, discovered in 1939 from the soil bacterium Bacillus brevis, was the first antibiotic to be manufactured commercially.

A second significant discovery followed soon after: gramicidin S was discovered by Russian microbiologist Georgyi Frantsevitch Gause and his wife Maria Brazhnikova in 1942. Within the year, gramicidin S was being used in Soviet military hospitals to treat infection. Another cyclic polypeptide, from another strain of B. brevis, gramicidin S (where "S" stands for Soviet), was reported in 1944.

These early uses of Brevibacillus-derived products represent a form of traditional pharmaceutical use in 20th-century medicine. Gramicidins are used in medicinal lozenges for sore throat and in topical medicines to treat infected wounds. Gramicidins are often mixed with other antibiotics like tyrocidine and antiseptics. Gramicidins are also used in eye drops for bacterial eye infections. These clinical applications, established in the 1940s, represent the earliest documented practical deployment of Brevibacillus-derived materials in human health.

3. Key Constituents and Active Compounds

Brevibacillus is a rich resource for antimicrobials, and many compounds have been isolated and characterized. Members of the genus Brevibacillus have been demonstrated to produce a variety of bioactive compounds including polyketides, lipopeptides, and bacteriocins. Lipopeptides are non-ribosomally synthesized surface-active compounds with antimicrobial, antitumor, and immune-stimulatory activities. They usually exhibit strong antifungal and antibacterial activities and are considered as promising compounds in controlling fungal diseases.

Bioactive peptides produced by Brevibacillus spp. include antibacterial, antifungal, and anti-invertebrate agents. Brevibacillus antimicrobial peptides are synthesized through ribosomal or nonribosomal pathways; these two groups can be further categorized based on specific structural features such as cyclization and presence of a lipid chain.

3.1 Compounds from Brevibacillus brevis

• Gramicidin (A, B, C): Gramicidin, a linear pentadecapeptide antibiotic, is biosynthesized through nonribosomal peptide synthesis (NRPS) by large multimodular enzyme complexes in the bacterium Brevibacillus brevis. This pathway operates independently of ribosomal machinery, utilizing modular nonribosomal peptide synthetases (NRPSs) to assemble the peptide from activated amino acid monomers in a template-free manner. The process involves four distinct NRPS enzymes, designated LgrA, LgrB, LgrC, and LgrD, which together contain 16 modules and 56 catalytic domains responsible for the sequential incorporation of 15 amino acids. In its native production, gramicidin forms part of the tyrothricin complex, a mixture of peptide antibiotics that also includes tyrocidines. The tyrothricin complex typically consists of approximately 20% gramicidin and 80% tyrocidines.
• Gramicidin S: Gramicidin S is produced by the Gram-positive bacterium Brevibacillus brevis. It is a cyclodecapeptide, constructed as two identical pentapeptides joined head to tail. That is, it forms a ring structure composed of five different amino acids, each one used twice. It utilizes two amino acids uncommon in peptides: ornithine as well as the atypical stereoisomer of phenylalanine.
• Tyrocidine: Tyrothricin was isolated from Brevibacillus brevis and appeared to be a mix of cyclic and linear polypeptides with antimicrobial activity. Its principal component is tyrocidine, which is a mixture of cyclic decapeptides. The nonribosomal biosynthesis of tyrocidine is via an enzymatic assembly consisting of three peptide synthetase proteins, TycA, TycB, and TycC, which contain 10 modules.
• Loloatins A–D: Gramicidin S, loloatins, and tyrocidines were discovered from Brevibacillus brevis.

3.2 Compounds from Brevibacillus laterosporus

• Brevibacillin: B. laterosporus OSY-I₁ produces brevibacillin, a 1583 Da antimicrobial lipopeptide with a linear structure containing 13 amino acids and a C₆ fatty acid at the N-terminus. Brevibacillin shows strong antimicrobial activity against some pathogenic and food-spoilage Gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus. Brevibacillin is produced by Brevibacillus laterosporus and consists of 13 amino acids with an N-terminal C₆-fatty acid chain. It has a molecular mass of 1583 Da and contains three modified amino acid residues: valinol, D-ornithine, and α,β-didehydrobutyric acid (Dhb).
• Brevicidine: ESI-MS/MS spectroscopy and NMR analysis confirmed brevicidine as a distinct compound. Brevicidine displayed notable antibacterial activity against Gram-negative bacteria, with a minimum inhibitory concentration (MIC) range of 1–8 μg/mL. Brevicidine exhibited no hemolysis or cytotoxicity up to 512 μg/mL, comparable to the negative control, suggesting its promising therapeutic potential in treating infectious diseases.
• Laterosporulin: Laterosporulin is active against both Gram-positive and Gram-negative bacteria and was found to be resistant to a range of proteolytic enzymes. Structural studies revealed that the peptide consists of twisted β-sheet and includes three disulfide bonds. Laterosporulin is relatively rich in cysteine and polar amino acids, which is atypical for bacteriocins in general, whereas its structure showed similarities with mammalian defensins.
• Tauramamide, Bogorols, and Brevibacillin Variants: Tauramamide, bogorols, laterosporulin, and other compounds were isolated from B. laterosporus. Bogorol A–E, brevibacillin, and brevibacillin V are produced by various Brevibacillus laterosporus strains and can all be grouped into the family of non-ribosomally produced linear lipo-tridecapeptides. These lipo-tridecapeptides show strong antimicrobial activity against Gram-positive pathogenic bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus spp.
• Relacidines and Laterocidine: Brevicidine, laterocidine, and relacidines — a class of cationic lipopeptides that selectively combat Gram-negative bacteria — were characterized from B. laterosporus.
• Brevilaterins: The bactericidal activity of brevilaterins secreted by B. laterosporus is attributed to their ability to bind to lipopolysaccharide/lipid II molecules on the cell membrane, thereby altering permeability. Brevilaterins also inhibit bacterial reproduction by affecting relevant gene pathways in the cell membranes of pathogenic bacteria. These pathways include ATP synthesis, peptidoglycan biosynthesis, membrane transport, and cellular metabolism.
• Diketopiperazines: LC-MS/MS investigation of B. laterosporus extract and molecular networking database analysis demonstrated five strategic diketopiperazine compounds with antimicrobial and anticancer activities. This research shows that the crude extract of B. laterosporus might be an effective agent against drug-resistant bacteria and malignant disorders due to its richness in diketopiperazines.
• Chitinases: B. laterosporus also produces enzymes relevant to biocontrol. The multi-chitinolytic complex from Brevibacillus laterosporus Lak 1210 has shown excellent chitin degradation ability, insecticidal activity against lepidopteran insects, as well as antifungal activity against several phytopathogenic fungi.

4. Established Mechanisms of Action

4.1 Membrane Disruption

The mechanism of action of gramicidins and related polypeptides is as follows: they act as channels and increase the permeability of the bacterial cell membrane when incorporated, thus destroying the ion gradient between the cytoplasm and the extracellular environment. Gramicidin A is a peptide antibiotic that disrupts the transmembrane ion concentration gradient by forming an ion channel in a lipid bilayer. Although long used clinically, it is limited to topical application because of its strong hemolytic activity and mammalian cytotoxicity, likely arising from the common ion transport mechanism.

For brevibacillin and related lipo-tridecapeptides, the mechanism of action is most likely based on its amphiphilic nature and the ability of cationic amino acids to interact with the negatively charged phospholipids of the cell membrane, causing the disruption and depolarization of the membrane.

Tyrocidine has a unique mode of action in which it disrupts cell membrane function. Tyrocidine appears to perturb the lipid bilayer of a microbe's inner membrane by permeating the lipid phase of the membrane.

4.2 Antimicrobial Peptide Biosynthesis via NRPS

Brevibacillus antimicrobial peptides are synthesized through ribosomal or nonribosomal pathways; these two groups can be further categorized based on specific structural features such as cyclization and presence of a lipid chain. The nonribosomal peptide synthetase (NRPS) pathway enables the incorporation of non-canonical and D-amino acids, which due to the presence of non-canonical amino acids, D-amino acids, and several other modifications, confer commonly good proteolytic stability.

4.3 Probiotic / Microbiota Modulation Mechanisms

B. laterosporus enhances crop cultivation by secreting hydrolases to improve nutrient absorption capabilities, synthesizing hormones to promote crop growth, and producing proteins to inhibit the reproduction of harmful organisms. In animal production contexts, B. laterosporus has been used to improve animal production by regulating the structure of the intestinal microbiota and inhibiting the growth of pathogenic bacteria through the secretion of various antimicrobial peptides.

B. laterosporus, which produces a variety of metabolites including antimicrobial peptides and enzymes, exhibits a wide range of antimicrobial activity against bacteria, fungi, and protozoa.

5. Scientific Evidence by Area of Use

5.1 Antimicrobial Activity (In Vitro Evidence)

Evidence level: Extensive in vitro; very limited clinical human data.

Different species of Brevibacillus show broad-spectrum antimicrobial activity, including activity against bacteria and fungi. A variety of molecules, including proteins and antibiotics, have been associated with their observed pathogenicity and mode of action. The antifungal and antibacterial properties of some Brevibacillus species found medical interest, linked to the production of antibiotics with therapeutic effects.

Specific in vitro MIC data for brevibacillin against clinically important bacteria has been reported: brevicidine displayed notable antibacterial activity against Gram-negative bacteria, with an MIC range of 1–8 μg/mL, while brevibacillin exhibited robust antimicrobial effectiveness against Gram-positive bacterial strains (MIC range of 2–4 μg/mL) and Gram-negative bacteria (MIC range of 4–64 μg/mL).

Regarding activity against multidrug-resistant organisms, a B. laterosporus strain designated XJ-24-3 exhibited bactericidal activity against diverse foodborne pathogens, including methicillin-resistant Staphylococcus aureus. Significant antimicrobial activity was reported for brevibacillin and its analogs against Gram-positive and some Gram-negative bacteria implicated in foodborne disease. Brevibacillin isolated from B. laterosporus OSY-I₁ exhibits substantial inhibition of methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes, Escherichia coli, and Pseudomonas aeruginosa.

A study on bacteriocin-like substances from B. laterosporus SA-14 examined potential wound healing applications: the study aimed to enhance production of bacteriocin-like substances (BLS) from Brevibacillus laterosporus SA-14 by optimizing nutrients, evaluating antibacterial activity, assessing synergy with vancomycin, and testing cytotoxicity and wound healing effects on human keratinocytes. This represents a promising but preliminary in vitro direction.

A novel brevibacillin variant, brevibacillin 2V, showed improved safety markers: brevibacillin 2V has a much lower hemolytic activity (HC₅₀ > 128 mg/L) and cytotoxicity (CC₅₀ = 45.49 ± 0.24 mg/L) to eukaryotic cells than previously reported NRPs of the lipo-tridecapeptide family, including other brevibacillins, making it a promising candidate for antibiotic development.

Importantly, in animals and humans, gramicidin activity, at concentrations lower than needed to achieve the bacterial killing effect, induces hemolysis. Thus, topical applications require the skin or mucosa surface to be intact to prevent systemic entry. No completed human clinical trials on Brevibacillus-derived antimicrobial peptides for systemic infections have been identified in the published literature.

5.2 Probiotic Effects on Gut Microbiota and Metabolic Parameters (Animal Evidence)

Evidence level: Preclinical (rodent and avian models); no controlled human trials identified.

A key study in a rodent model examined anti-obesity effects: the study investigated the effects of Brevibacillus laterosporus BL1 on preventing obesity in high-fat diet (HFD)-fed mice. C57BL/6 male mice were randomly assigned to four groups (n = 10) and fed a control diet, HFD, HFD plus B. laterosporus BL1, and HFD plus supernatant of B. laterosporus BL1, respectively for 8 weeks. The results showed that prophylactic B. laterosporus BL1 treatment reduced body weight gain by 41.26% in comparison to the HFD group, accompanied by reductions in body fat mass and white adipose tissue weights. The B. laterosporus BL1-mediated improvements in lipid profile, insulin resistance, and chronic inflammation were associated with the regulation of gene expression related to lipid metabolism and enhancement of brown adipose tissue thermogenesis. B. laterosporus BL1 intervention significantly improved HFD-induced gut flora dysbiosis, as evidenced by reversal of the relative abundance of Bacillota and Bacteroidota, as well as an increase in relative abundance of short-chain fatty acid (SCFA)-producing bacteria.

A broader review of gut microbiome effects noted that B. laterosporus BL1 intervention modulated HFD-induced structural and compositional alteration of gut microbiota, including a decrease in the relative abundance of Bacillota and Faecalibaculum and an increase in the relative abundance of Bacteroidota and norank_f_Muribaculaceae, accompanied by an elevation in short-chain fatty acid (SCFA) production.

These findings are animal-only. The authors found for the first time that B. laterosporus BL1 may be a promising probiotic for prevention of obesity associated with the regulation of gut microbiota. There are no human clinical trials confirming these effects.

5.3 Effects in Poultry Production (Animal Evidence)

Evidence level: Multiple controlled animal feeding studies; no human data.

A broiler study using strain S62-9 at 10⁶ CFU/g feed: a total of 160 one-day-old broilers were randomly divided into S62-9 and control groups, with or without 10⁶ CFU/g B. laterosporus S62-9 supplementation, respectively, during 42 days feeding. After 42 days of feeding, broilers in the S62-9 group had higher body mass (7.2%) and feed conversion ratio (5.19%) than the control group. Supplementation with B. laterosporus S62-9 resulted in lower serum total cholesterol and low-density lipoprotein-cholesterol concentrations and higher high-density lipoprotein-cholesterol concentrations.

A 2025 study in Scientific Reports examined immune and gut health endpoints: the study evaluated Brevibacillus laterosporus (PBC01) on growth performance, immunity and intestinal health of male Lohmann Brown laying chickens. A total of 144 seven-day-old chickens were randomly assigned to four dietary treatments: a basal diet supplemented with 0%, 0.10%, 0.25%, or 0.50% (w/w) B. laterosporus PBC01 powder (1.0 × 10⁹ cfu/g), fed for 56 days. Results showed that supplementary feeding with 0.25% PBC01 could enhance the chicken's antioxidant capacity and improve body weight gain and feed conversion ratio throughout the experimental period. PBC01 also promoted the relative weight of immune organs, enhanced lymphocyte conversion in peripheral blood, and reduced the mRNA expression of IL-2, IL-4, IL-6, and TNF-α in spleen.

A 2024 multi-dose broiler study employed doses of 100 mg/kg, 300 mg/kg, and 500 mg/kg: a total of 320 one-day-old male broilers were randomly assigned to four dietary groups: control (CON), low-dose (LBL, 100 mg/kg), medium-dose (MBL, 300 mg/kg), and high-dose (HBL, 500 mg/kg) B. laterosporus supplementation. Dietary supplementation with B. laterosporus significantly decreased the feed intake/weight gain ratio in LBL, MBL, and HBL groups; both MBL and HBL groups showed higher semi-eviscerated percentages than the control. Dietary supplementation with B. laterosporus significantly enhanced oxidative stress resistance by decreasing malondialdehyde (MDA) levels and increasing glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC). 16S ribosomal DNA and metabolome sequencing of cecum contents demonstrated significant increases in α-diversity indices. There was an increased relative abundance of Firmicutes and a decreased relative abundance of Bacteroidetes and Proteobacteria.

5.4 Antioxidant Activity (Animal Evidence)

Evidence level: Animal studies only; no human clinical evidence.

Dietary supplementation with B. laterosporus significantly enhanced the oxidative stress resistance of serum by decreasing malondialdehyde (MDA) levels and increasing glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC). These effects have been observed across multiple poultry feeding experiments but have not been replicated in human subjects.

5.5 Anticancer Activity (In Vitro / Preclinical Evidence Only)

Evidence level: In vitro cell-line data only; no animal or human trials.

Laterosporulin 10 (LS10), a defensin-like bacteriocin from Brevibacillus sp. SKDU10, has been studied in cancer cell lines: LS10 displayed cytotoxicity against cancer cells including MCF-7, HEK293T, HT1080, HeLa, and H1299 at below 10 μM concentration, but not against prostate epithelium cells RWPE-1. Additionally, no hemolysis was observed at significantly higher concentrations compared to IC₅₀ values observed for different cancer cell lines.

In a separate study, brevilaterin B from B. laterosporus S62-9 was evaluated in epidermal cancer cell lines: brevilaterin B exhibited broad-spectrum anticancer activity in a dose-dependent manner. It selectively inhibited the proliferation of epidermal cancer cell A431 but had no effect on its control normal cells at a dose of 2.0 μg/mL.

The cytotoxicity of a methanolic extract of B. laterosporus against breast cancer (MCF-7) and normal Vero cell lines, using the MTT test, revealed IC₅₀ values of 7.93 and 23.79 μg/mL, respectively. Flow cytometric analysis recorded a higher number of necrotic cells compared to apoptotic ones. Cell cycle S-phase arrest was also reported.

Broad-spectrum antimicrobial action against drug-resistant and pathogenic bacteria along with antitumor activities suggests the potential for development of bioactive molecules produced by B. laterosporus in the pharmaceutical and biotechnology industry. However, all anticancer findings to date derive from cell-line assays and have not been evaluated in animal or human models.

5.6 Agricultural and Biocontrol Applications (Laboratory and Greenhouse Evidence)

Brevibacillus laterosporus is widely distributed in nature and demonstrates significant potential for applications in biological control, environmental protection, agricultural production, and clinical medicine. B. laterosporus enhances crop cultivation by secreting hydrolases to improve nutrient absorption capabilities, synthesizing hormones to promote crop growth, and producing proteins to inhibit the reproduction of harmful organisms.

In greenhouse settings, the B. laterosporus strain BPM3 suppressed blast disease of rice by 30–67% and protected weight loss by 35–56.5% in greenhouse experiments.

The insecticidal properties have been exploited in livestock settings: the oral administration of the entomopathogenic bacterium Brevibacillus laterosporus to caged poultry species allows homogeneous incorporation of its active ingredients with fly breeding media. Feces from treated broilers or hens show toxicity against exposed fly adults and larvae. Insecticidal effects are concentration-dependent, with a lethal median concentration (LC₅₀) value of 1.34 × 10⁸ and 0.61 × 10⁸ spores/g of feces for adults and larvae, respectively.

6. Body Systems and Health Areas

Based on the published evidence, Brevibacillus and its derived compounds have been associated with the following body systems and health domains:

• Gastrointestinal System: As a spore-forming probiotic, B. laterosporus has been studied for modulation of gut microbiota composition, enhancement of intestinal barrier function, and promotion of SCFA production in animal models.
• Immune System: PBC01 supplementation promoted the relative weight of immune organs, enhanced lymphocyte conversion in peripheral blood, and reduced mRNA expression of IL-2, IL-4, IL-6, and TNF-α in spleen.
• Metabolic / Cardiovascular System: In animal models, B. laterosporus BL1 has been associated with regulation of lipid profiles, insulin sensitivity, and adipogenesis. B. laterosporus BL1, originally isolated from earthworm intestines, exerts regulatory effects on lipid metabolism in mice by stimulating lipolysis in white adipose tissue and promoting thermogenesis in brown adipose tissue.
• Antioxidant / Redox Pathways: Animal feeding studies have documented increases in systemic antioxidant markers (T-AOC, GSH-PX) and reductions in lipid peroxidation marker MDA.
• Dermatological / Wound Healing (Topical): Gramicidin-derived preparations are used topically for infected wounds, sore throat, and ocular infections.
• Oncology (Preclinical Only): In vitro data indicate cytotoxicity of bacteriocins such as laterosporulin 10 and brevilaterin B against several cancer cell lines.

7. Dosage Forms and Reported Dosages

The following dosages have been reported specifically in published scientific studies. All figures refer to animal or laboratory contexts, as no standardized human dosing exists in the literature reviewed.

• In a poultry laying hen study, basal diets were supplemented with 0%, 0.10%, 0.25%, or 0.50% (w/w) B. laterosporus PBC01 powder at a concentration of 1.0 × 10⁹ CFU/g, fed for 56 days.
• In a broiler study, supplementation doses of 100 mg/kg (low), 300 mg/kg (medium), and 500 mg/kg (high) of B. laterosporus were tested in 320 one-day-old male broilers.
• In another broiler growth study, 10⁶ CFU/g B. laterosporus S62-9 supplementation was administered to 160 one-day-old broilers over 42 days.
• In a finishing pig study, the treatment groups received a basal diet supplemented with 0.5% live B. laterosporus BL1 or 0.5% heat-killed B. laterosporus BL1.
• In the rodent obesity model, C57BL/6 male mice (n = 10 per group) were fed an HFD with or without B. laterosporus BL1 for 8 weeks. The exact CFU dose in the mouse study was not reported in the available abstract.
• For topical gramicidin preparations, gramicidins are used in medicinal lozenges for sore throat, in topical medicines to treat infected wounds, and in eye drops for bacterial eye infections, often mixed with other antibiotics such as tyrocidine, polymyxin B, or neomycin. Specific concentrations in these products vary by formulation and are governed by individual regulatory approvals.

8. Safety Considerations and Interactions

8.1 General Environmental and Exposure Safety

Brevibacillus laterosporus is ubiquitous in the environment, implying widespread human and animal exposure, and does not have any reported allergenic history. Additionally, proteins derived from B. laterosporus degrade rapidly when exposed to digestive enzymes (gastric proteases) present in the human gastrointestinal tract, and show loss of function under high temperatures (≥75 °C), indicating that they are heat labile and will likely denature in the course of normal thermal treatment during food preparation.

8.2 Hemolytic Activity of Gramicidin and Related Peptides

A critical and well-documented safety concern for the primary bioactive compounds of Brevibacillus brevis is their hemolytic potential when administered systemically. Gramicidins and related polypeptides act as membrane channels, increasing cell membrane permeability. In animals and humans, this activity, at concentrations lower than needed to achieve the bacterial killing effect, induces hemolysis. Thus, topical applications require the skin or mucosa surface to be intact to prevent systemic entry. Gramicidin A is limited to topical application because of its strong hemolytic activity and mammalian cytotoxicity, likely arising from the common ion transport mechanism.

Similarly, tyrocidine and gramicidin were observed to have toxic effects in red blood cells and reproductive cells in humans; however, if applied externally as an ointment, tyrocidine could be used as a potent antimicrobial agent.

8.3 Cytotoxicity of Brevibacillin

Whereas brevicidine showed favorable safety markers in vitro, brevibacillin demonstrated a more concerning profile: brevibacillin demonstrated elevated cytotoxicity in in vitro assays. Nonetheless, owing to its noteworthy antimicrobial activity against pathogenic bacteria, brevibacillin could still be explored as a promising antimicrobial agent. The synthetic analog brevibacillin Thr1 was engineered in part to address this: the latter is a 1602.13 Da positively charged synthetic peptide of 13 residues that showed reduced cytotoxicity (IC₅₀ of 32.2 μg/mL against Caco-2 cells) and hemolytic activity (1.2% hemolysis at 128 μg/mL) compared to the native peptide.

8.4 Rare Opportunistic Infection Risk

Although B. laterosporus is generally regarded as non-pathogenic in healthy individuals, there is a documented case of infection in an immunocompromised patient. A case report described what is believed to be the first reported case of B. laterosporus bacteremia in an adult human subject. Brevibacillus laterosporus is an aerobic Gram-positive bacillus found in soil and aquatic environments. This "canoe-shaped" microbe was a member of the Bacillus genus until 1996 when a 16S rRNA sequence study showed it to be phylogenetically distinct. Reports of human B. laterosporus infection are scarce. The bacteremia in the reported case occurred in the context of an indwelling catheter and was successfully treated with antibiotics.

8.5 Laboratory Biosafety Classification

For laboratory handling, reference culture collections apply specific biosafety designations. Researchers should be aware that biosafety classifications apply to laboratory handling contexts and may not directly translate to risk levels for dietary or probiotic preparations of defined strains.

8.6 Probiotic Safety Profile in Animal Studies

Previous laboratory studies have shown that B. laterosporus has a wide range of probiotic properties and good safety. Both live and heat-killed B. laterosporus BL1 supplementation in finishing pigs increased pH24h and decreased drip loss, with heat-killed BL1 exhibiting stronger improvements in meat quality, antioxidant capacity, and free amino acid profiles without impairing porcine growth performance. Across the reviewed animal feeding studies, no adverse effects attributable to B. laterosporus supplementation were reported at the tested doses.

8.7 Status as a Feed Additive

Brevibacillus laterosporus is a biocontrol bacterium with broad-spectrum antimicrobial activity and insecticidal properties and has been permitted as a microbial feed additive for livestock and poultry. This regulatory approval pertains to animal feed contexts, not human dietary supplements, and the regulatory frameworks for human probiotic use would require separate evaluation.

9. Research Limitations and Evidence Gaps

The current body of evidence for Brevibacillus as a human dietary supplement or probiotic has several important limitations. The majority of beneficial effects, including gut microbiota modulation, antioxidant activity, immune enhancement, and metabolic improvements, derive from animal feeding experiments in poultry and rodents. No controlled human clinical trials have been identified that evaluate Brevibacillus laterosporus or related species as a probiotic in human subjects. Anticancer findings are restricted to in vitro cell-line data and have not been validated in vivo. The hemolytic and cytotoxic properties of gramicidin and certain related peptides preclude their systemic use in humans, limiting their clinical application to topical formats where they are already established. B. laterosporus exhibits substantial potential as a probiotic in crop and animal production; however, applications in animal production could be improved, necessitating further research to elucidate the underlying probiotic mechanisms.

References

• PMC7818431 – Characterization of two relacidines belonging to a novel class of circular lipopeptides from Brevibacillus laterosporus MG64 (PMC / Frontiers in Microbiology, 2021)
• PMC6510442 – Brevibacillus laterosporus strains BGSP7, BGSP9 and BGSP11 isolated from silage produce broad spectrum multi-antimicrobials (PMC, 2019)
• Antimicrobial peptides produced by Brevibacillus spp.: structure, classification and bioactivity: a mini review (World Journal of Microbiology and Biotechnology, 2018)
• Novel Modifications of Nonribosomal Peptides from Brevibacillus laterosporus MG64 (Applied and Environmental Microbiology, ASM, 2021)
• PMC10984550 – New strain Brevibacillus laterosporus TSA31-5 produces both brevicidine and brevibacillin (PMC, 2024)
• A probiotic Brevibacillus laterosporus promotes chicken growth performance, immunity and gut health (Scientific Reports, Nature, 2025)
• PMC9729748 – Brevibacillus laterosporus BL1, a promising probiotic, prevents obesity and modulates gut microbiota in mice fed a high-fat diet (PMC, 2022)
• Brevibacillus laterosporus: A Probiotic with Important Applications in Crop and Animal Production (MDPI Microorganisms, 2024)
• PMC10975594 – Brevibacillus laterosporus: A Probiotic with Important Applications in Crop and Animal Production (PMC, 2024)
• PMC12213765 – Effect of dietary supplementation with Brevibacillus laterosporus on broiler growth performance, meat quality and gut microbiome (PMC, 2025)
• PMC9858446 – Dietary Effect of Brevibacillus laterosporus S62-9 on Chicken Meat Quality, Amino Acid Profile, and Volatile Compounds (PMC, 2023)
• Effects of dietary Brevibacillus laterosporus BL1 supplementation on meat quality, antioxidant capacity, and the profiles of muscle amino acids and fatty acids in finishing pigs (ScienceDirect / Meat Science, 2024)
• Brevibacillus brevis – Overview (ScienceDirect Topics / Pharmacology)
• Brevibacillus brevis – Overview (ScienceDirect Topics / Agricultural and Biological Sciences)
• Genus: Brevibacillus (List of Prokaryotic names with Standing in Nomenclature, DSMZ-LPSN)
• Brevibacillus – Logan (Bergey's Manual / Wiley Online Library)
• Anticancer properties of a defensin-like class IId bacteriocin Laterosporulin10 (Scientific Reports, Nature, 2017)
• PMC9699243 – Structural Diversity, LC-MS-MS Analysis and Potential Biological Activities of Brevibacillus laterosporus Extract (PMC, 2022)
• PMC8245773 – Brevibacillin 2V, a Novel Antimicrobial Lipopeptide With an Exceptionally Low Hemolytic Activity (PMC / Frontiers in Microbiology, 2021)
• Brevilaterin B from Brevibacillus laterosporus has selective antitumor activity and induces apoptosis in epidermal cancer (World Journal of Microbiology and Biotechnology, 2022)
• PMC12111383 – Antimicrobial Activity of a Synthetic Brevibacillin Analog Against Multidrug-Resistant Campylobacter spp. (PMC, 2025)
• PMC11869030 – Investigating the production and synergistic antibacterial activity of bacteriocin-like substance from Brevibacillus laterosporus SA-14 for enhanced wound healing (PMC, 2025)
• PMC7567323 – Brevibacillus laterosporus Bacteremia in an Adult (PMC / Case Report, 2020)
• Discovery of gramicidin A analogues with altered activities by multidimensional screening (Nature Communications, 2020)
• Administration of Brevibacillus laterosporus spores as a poultry feed additive to inhibit house fly development in feces (ScienceDirect / Poultry Science, 2020)
• Brevibacillus laterosporus: a co-evolving machinery of diverse antimicrobial agents (PubMed, 2025)
• Brevibacillus laterosporus strain BPM3, a potential biocontrol agent isolated from a natural hot water spring of Assam, India (ScienceDirect, 2010)
• Brevibacillus brevis (Wikipedia – for taxonomic background only)
• Gramicidin (Wikipedia – for historical compound overview)
• Gramicidin S (Wikipedia – for historical and structural overview)
• Gramicidin – The Rockefeller University Hospital Centennial (historical account of Dubos discovery)
• Dietary Supplementation of Brevibacillus laterosporus S62-9 Improves Broiler Growth and Immunity by Regulating Cecal Microbiota and Metabolites (PubMed, 2023)
• Effect of dietary supplementation with Brevibacillus laterosporus on broiler growth performance, meat quality and gut microbiome (Frontiers in Microbiology, 2025)
• EPA Regulatory Assessment: Brevibacillus laterosporus Mpp75Aa1.1 Safety Data (EPA, 2024)
• PMC12503217 – Antibacterial activity and genomic characterisation of a novel Brevibacillus laterosporus XJ-24-3 (PMC, 2025)