Scientists discovered that a substance created from a helpful bacteria called Lacticaseibacillus paracasei BGP1 can kill dangerous germs that don’t respond to regular antibiotics. These germs commonly infect skin wounds and are becoming harder to treat. The researchers tested this probiotic byproduct, called a postbiotic, in the lab against four types of harmful bacteria, including a dangerous strain called MRSA. The postbiotic worked well and stayed stable, making it a promising candidate for creating new wound treatments without needing to use live bacteria.

The Quick Take

  • What they studied: Whether a byproduct made from beneficial bacteria could kill germs that resist normal antibiotics, especially those that infect skin wounds
  • Who participated: This was laboratory research testing six different probiotic strains against four types of bacteria commonly found in skin infections. No human participants were involved in this study.
  • Key finding: The postbiotic from BGP1 bacteria successfully killed multiple antibiotic-resistant germs in lab tests, with the strongest effect at a concentration of 12.5 mg/mL. The substance remained stable and effective, unlike live bacteria which can break down easily.
  • What it means for you: This research suggests a potential new way to treat stubborn skin wound infections that don’t respond to regular antibiotics. However, this is early-stage research—much more testing in animals and humans is needed before this could become an actual treatment you could use.

The Research Details

Researchers collected a liquid byproduct from six different probiotic bacteria strains. This liquid, called a cell-free supernatant, contains helpful substances the bacteria produce but doesn’t contain the living bacteria themselves. They tested this liquid against four types of dangerous bacteria that commonly infect skin wounds, including a particularly tough strain called MRSA (methicillin-resistant Staphylococcus aureus) that doesn’t respond to many antibiotics.

The scientists used two main testing methods. First, they used agar well diffusion, which involves putting the probiotic liquid into small wells on a plate of bacteria to see if it creates a clear zone where bacteria can’t grow. Second, they used broth microdilution, which tests different concentrations of the liquid to find the exact amount needed to stop bacterial growth (called the MIC) and the amount needed to actually kill the bacteria (called the MBC).

Finally, they used a technique called GC-MS analysis to identify exactly which compounds in the most effective postbiotic were responsible for killing the bacteria.

This research approach is important because it addresses a real problem in dermatology (skin medicine). Live probiotic bacteria are difficult to use in skin products because they break down easily in water-based formulas. By studying the byproducts these bacteria create instead of the bacteria themselves, researchers found a more stable alternative that could actually be used in real skin treatments.

This is laboratory research, which means it was conducted in controlled conditions with pure bacterial cultures. The study used standardized bacterial strains from recognized collections, which makes the results reproducible. However, laboratory results don’t always translate to real-world effectiveness in human skin. The study is relatively small in scope (testing six strains) and doesn’t include animal or human testing yet, so the findings are preliminary.

What the Results Show

Among the six probiotic strains tested, Lacticaseibacillus paracasei BGP1 showed the most consistent and powerful antibacterial effects. It successfully inhibited (stopped the growth of) all four types of bacteria tested at a concentration of 6.25 mg/mL. At a slightly higher concentration of 12.5 mg/mL, it actually killed the bacteria rather than just stopping their growth.

This was particularly impressive against MRSA, the antibiotic-resistant strain that causes serious skin infections and is notoriously difficult to treat. The postbiotic worked against both common Staphylococcus aureus bacteria and the more dangerous MRSA variant, as well as two types of Pseudomonas aeruginosa bacteria.

When researchers analyzed what was actually in this effective postbiotic, they found it was primarily made up of two fatty acids: palmitic acid (about one-third) and stearic acid (about half). These natural compounds appear to be responsible for the antibacterial power.

The other five probiotic strains tested showed less consistent results, with weaker antibacterial effects compared to BGP1. This suggests that not all probiotics produce equally effective byproducts, and the specific strain matters significantly. The stability of the postbiotic is also noteworthy—unlike live bacteria that need special storage conditions, this cell-free supernatant remained effective, suggesting it could be easier to formulate into actual products.

Most previous research on probiotics for fighting infections has focused on either using live bacteria or testing them when taken by mouth. This study fills a gap by testing the byproducts of probiotics specifically for skin wound applications. The finding that simple fatty acids are responsible for the antibacterial effect aligns with previous research showing that certain fatty acids have natural antimicrobial properties. However, this is one of the first studies to systematically evaluate postbiotics from this specific bacterial strain against antibiotic-resistant skin pathogens.

This research was conducted entirely in laboratory dishes and test tubes, not in living organisms. The bacteria tested were pure laboratory strains, not the complex mix of bacteria found in real skin infections. The study doesn’t tell us whether this postbiotic would actually work on real skin wounds or whether it could cause any side effects. Additionally, the study doesn’t specify exactly how many independent experiments were performed or provide detailed statistical analysis. Before this could become a treatment, researchers would need to test it in animal models and eventually in human clinical trials.

The Bottom Line

Based on this early research, there is promising potential for postbiotics from L. paracasei BGP1 to be developed into treatments for antibiotic-resistant skin infections. However, confidence in this recommendation is currently low because the research is preliminary. Do not attempt to use this as a treatment yet—it exists only in laboratory form. Anyone with a skin wound infection, especially one that hasn’t responded to antibiotics, should continue following their doctor’s current treatment recommendations while researchers continue developing this approach.

This research is most relevant to dermatologists, wound care specialists, and pharmaceutical companies developing new treatments for antibiotic-resistant infections. People with chronic skin wounds or recurrent infections may eventually benefit, but not yet. This is not appropriate for self-treatment or over-the-counter use at this stage. Healthcare providers treating patients with MRSA or other antibiotic-resistant skin infections should be aware of this emerging research but should not change current treatment protocols based on this single laboratory study.

If this research progresses as hoped, the realistic timeline would be: 1-2 years for animal testing, 2-5 years for early human trials, and potentially 5-10 years before a product could be available to patients, assuming all testing goes well. Many promising laboratory findings never make it to clinical use, so this timeline is optimistic.

Want to Apply This Research?

  • Users with chronic skin wounds could track wound healing progress by photographing the wound weekly in consistent lighting and measuring the wound size. They could also track any signs of infection (increased redness, warmth, drainage, or odor) to monitor whether current treatments are working.
  • While this specific postbiotic isn’t available yet, users could use the app to track their adherence to current wound care protocols: daily cleaning, dressing changes, antibiotic application if prescribed, and follow-up appointments. This data will be valuable when new treatments become available.
  • Set up a long-term tracking system that records wound appearance, infection signs, and treatment effectiveness. This creates a baseline for comparison if new postbiotic treatments become available in the future. Users should also track any new research or clinical trials related to postbiotics for skin infections through the app’s news or research update features.

This research is preliminary laboratory work and does not represent an approved treatment. Do not attempt to self-treat skin infections with probiotics or postbiotics without medical supervision. If you have a skin wound infection, especially one that isn’t responding to antibiotics, consult a healthcare provider immediately. This article is for educational purposes only and should not replace professional medical advice. Always follow your doctor’s recommendations for treating skin infections. Future research may or may not confirm the effectiveness of these postbiotics in human patients.