Bacillus amyloliquefaciens
Also known as: B. amyloliquefaciens, Bacillus amyloliquefaciens
Overview
Bacillus amyloliquefaciens is a nonpathogenic, spore-forming Gram-positive probiotic bacterium naturally found in soil and the gastrointestinal tract of animals. It is utilized as a dietary supplement to modulate gut microbiota, enhance growth performance, and boost immunity, primarily in animal applications. Its primary uses include improving intestinal health, mitigating infections, and promoting growth in livestock. While research is ongoing, with numerous controlled animal studies and mechanistic insights, large-scale human randomized controlled trials (RCTs) and systematic reviews are currently limited. The bacterium's spore-forming nature contributes to its stability and survival through the harsh conditions of the gastrointestinal tract, enhancing its probiotic efficacy.
Benefits
Supplementation with Bacillus amyloliquefaciens has shown several benefits, primarily in animal models. It significantly modulates gut microbiota composition, increasing beneficial bacteria like Limosilactobacillus reuteri and restoring microbial homeostasis, as observed in mice infected with Schistosoma japonicum. This suggests a strong potential for improving overall gut health. In weaned pigs infected with enterotoxigenic Escherichia coli, B. amyloliquefaciens tended to improve average daily gain (ADG) and reduce diarrhea, indicating a moderate benefit for growth performance, though sometimes less pronounced than antibiotics. Furthermore, in calves, supplementation led to increased serum immunoglobulins (IgA, IgM, IgG) and growth factors (GH/IGF-1), correlating with improved body weight gain and feed efficiency. These benefits are consistent across animal studies, with moderate effect sizes typically observed over 3-4 weeks of supplementation.
How it works
Bacillus amyloliquefaciens primarily exerts its effects by modulating the gut microbiota. It increases populations of beneficial bacteria and helps restore functional gene profiles related to metabolism and urease activity within the intestine. This probiotic bacterium is believed to produce various enzymes and metabolites that contribute to improved nutrient absorption and the inhibition of pathogenic bacteria. A key aspect of its mechanism is its spore-forming capability, which confers high stability and allows it to survive the acidic environment of the stomach and colonize the gastrointestinal tract effectively, ensuring its bioavailability and sustained action.
Side effects
Bacillus amyloliquefaciens is generally considered safe and nonpathogenic, with no significant adverse effects reported in controlled animal studies. The reviewed research did not document any common, uncommon, or rare side effects. There are no known significant drug interactions or contraindications, but it is important to note that human data are very limited. Specific studies on special populations, such as immunocompromised individuals, have not been conducted with high-quality trials. Therefore, while animal data suggest a favorable safety profile, caution is advised for human use until more comprehensive clinical data become available.
Dosage
In animal studies, Bacillus amyloliquefaciens has been administered orally at doses ranging from approximately 10^8 to 10^9 Colony Forming Units (CFU) per day, typically for durations of 3 to 4 weeks. The optimal human dosage has not yet been established due to the lack of clinical trials in humans. Timing of supplementation often coincides with periods of stress or infection to maximize potential benefits. The spore form of the bacterium enhances its stability and absorption within the gastrointestinal tract, and no specific cofactors are reported to be required for its efficacy. Upper limits and safety thresholds for human consumption are currently undefined.
FAQs
Is Bacillus amyloliquefaciens safe for humans?
While animal studies suggest a good safety profile, human clinical trials are lacking. Caution is advised until more comprehensive human data are available to confirm safety and efficacy.
How long does it take to see benefits from Bacillus amyloliquefaciens?
Animal studies have shown that beneficial effects, such as improved growth and immune parameters, typically appear within 3-4 weeks of consistent supplementation.
Can Bacillus amyloliquefaciens replace antibiotics?
It may help reduce the reliance on antibiotics in livestock by improving gut health and immunity, but it is not a direct substitute for antibiotics in treating clinical infections.
Research Sources
- https://journals.asm.org/doi/10.1128/spectrum.03735-23 – This animal RCT with metagenomic analysis on mice infected with S. japonicum showed that B. amyloliquefaciens altered gut microbiota composition, increased beneficial bacteria, and alleviated pathological symptoms. It's a high-quality animal study with appropriate controls, providing mechanistic insights into gut modulation.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10050357/ – This RCT involving 50 weaned pigs infected with ETEC demonstrated that B. amyloliquefaciens supplementation tended to improve growth and reduce diarrhea, with some immune parameter improvements. It's a moderate-quality study with statistically significant trends, relevant for livestock applications despite modest effects.
- https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.02006/full – This controlled trial in calves showed that B. amyloliquefaciens increased growth factors and immunoglobulins, leading to improved feed conversion. It's a moderate-quality study relevant for livestock, though specific sample size details were limited.