Researchers developed a new way to edit the genes of popular probiotic bacteria (Lactiplantibacillus plantarum and Levilactobacillus brevis) to make them safer for human consumption. Using a technique called CRISPR gene editing, they turned off a gene called hlyIII that might cause harmful effects in the body. This new method is simpler and cheaper than previous approaches because it doesn’t require antibiotics or extra DNA plasmids. The edited bacteria showed reduced harmful activity in lab tests, suggesting this technology could help create better, safer probiotic supplements in the future.

The Quick Take

  • What they studied: Can scientists safely edit the genes of probiotic bacteria to remove a potentially harmful gene using a new CRISPR technique?
  • Who participated: Three different strains of probiotic bacteria commonly used in supplements and foods were tested in laboratory conditions
  • Key finding: Scientists successfully turned off the hlyIII gene in all three bacterial strains, and the edited bacteria showed reduced harmful activity in blood cells (27-74% reduction depending on the strain)
  • What it means for you: This research suggests future probiotic products could be made safer through genetic engineering, though more testing is needed before these edited bacteria are used in actual supplements or foods

The Research Details

Scientists selected three common probiotic bacteria strains and used a cutting-edge gene-editing tool called CRISPR-Cas9 to target and disable a specific gene (hlyIII). Instead of using the traditional method that requires antibiotics and extra DNA pieces, they used a simpler approach with a protein-RNA complex that acts like molecular scissors. They introduced this complex into the bacteria using electrical pulses, then checked if the gene was successfully disabled by reading the bacterial DNA and testing for harmful activity in blood cells.

The researchers chose to edit the hlyIII gene because it was suspected of causing hemolysis (breaking down red blood cells), which could be harmful if these bacteria were used in human products. However, this gene’s actual function hadn’t been clearly proven before this study.

This research matters because it demonstrates a faster, cheaper, and cleaner way to genetically improve probiotic bacteria. Previous methods required antibiotics and extra DNA, which could leave unwanted traces in the final product. This new approach is more practical for developing safer probiotic products that regulators and consumers might trust more. It also shows that this technique could work across different bacterial strains, making it broadly useful for probiotic engineering.

This is laboratory research conducted on bacterial strains in controlled conditions, not human testing. The study successfully demonstrated the technique worked, but the sample size was small (three bacterial strains). The findings are preliminary and would need additional validation, particularly in real-world conditions and eventually in human studies before these edited bacteria could be used in commercial products. The research was published in a peer-reviewed scientific journal, which means other experts reviewed it for quality.

What the Results Show

The researchers successfully edited the hlyIII gene in all three probiotic bacterial strains using their new CRISPR technique. DNA sequencing confirmed that a 50-base-pair section of the gene was deleted and a stop signal was introduced, effectively disabling the gene. When they tested the edited bacteria for harmful activity against blood cells, they found significant reductions compared to the original bacteria: a 27% reduction in one strain of L. plantarum, a 74% reduction in another L. plantarum strain, and a 5% reduction in the L. brevis strain.

The variation in results between different strains suggests that the hlyIII gene may work differently depending on the specific bacterial strain. This is important because it means scientists will need to customize their approach for different probiotic bacteria rather than using a one-size-fits-all solution.

The new editing method proved to be efficient and practical. Unlike older techniques, it didn’t require antibiotics to select the edited bacteria or leave behind extra DNA sequences that might be unwanted in a food or supplement product. This makes the edited bacteria cleaner and potentially more acceptable for use in human products.

The study also demonstrated that the CRISPR-RNP technique could be successfully applied to multiple different probiotic strains, suggesting the method has broad applicability. The researchers found that optimizing the electrical pulse conditions was important for successful gene editing, indicating that fine-tuning the process for each strain could improve results. The fact that different strains showed different levels of harmful activity reduction suggests that the hlyIII gene may have different roles in different bacteria, which could be important for future research.

Previous attempts to edit Lactobacillus bacteria using CRISPR have faced challenges with targeting specific sites and required more complex methods involving plasmids (extra DNA circles) and antibiotic resistance markers. This new ribonucleoprotein approach is simpler and more direct. Earlier research suggested the hlyIII gene might be harmful, but this is the first study to actually demonstrate reduced harmful activity when the gene is disabled. The results align with the growing scientific interest in using CRISPR for probiotic improvement, but this study provides a more practical method than previously published approaches.

This research was conducted entirely in laboratory conditions with bacterial cultures, not in living animals or humans. The sample size was very small (only three bacterial strains tested). The reduction in harmful activity was modest in some strains (only 5% in one case), raising questions about the practical significance. The study doesn’t prove that the hlyIII gene is actually responsible for the harmful activity—it only shows that disabling it reduces it somewhat. The long-term safety and stability of these edited bacteria haven’t been tested. Finally, these edited bacteria haven’t been tested in actual food or supplement products, so we don’t know how they would perform in real-world conditions.

The Bottom Line

Based on this research, there are no direct recommendations for consumers at this time. This is early-stage laboratory research. For scientists and probiotic manufacturers: this technique shows promise for creating safer probiotic strains and could be worth pursuing with further research. The confidence level is moderate—the technique works in the lab, but much more testing is needed before practical applications. Anyone considering using genetically edited probiotics should wait for human safety studies and regulatory approval.

Scientists and biotechnology companies developing probiotic products should pay attention to this research as it offers a new tool for improving bacterial strains. Regulatory agencies that approve food and supplement products should monitor this technology’s development. People with compromised immune systems or those taking probiotics therapeutically might eventually benefit from safer, engineered strains, but this is years away. General consumers don’t need to change their probiotic use based on this research—it’s too early stage.

This is fundamental research, not a product development study. It will likely take 3-5 years of additional laboratory work to fully characterize these edited bacteria. Human safety studies, if pursued, would add another 2-3 years minimum. Regulatory approval could take several more years. Realistically, edited probiotic products based on this technology might not be available to consumers for 5-10 years, if at all.

Want to Apply This Research?

  • Users could track their current probiotic use (brand, strain, daily dose) and any digestive symptoms or side effects in a daily log to establish a baseline. This would be useful for future comparison if engineered probiotics become available.
  • Users could set a reminder to research and note the specific bacterial strains in their current probiotic products. Understanding what strains they’re already taking will help them make informed decisions about future products as this technology develops.
  • Create a long-term tracking system for digestive health markers (bloating, regularity, energy levels, immune symptoms) that users can compare over time. This baseline data would be valuable for evaluating any new probiotic products that emerge from this research in the future.

This research describes laboratory work on bacterial gene editing and is not yet applicable to consumer products. These edited bacteria have not been tested in humans and have not received regulatory approval for use in food or supplements. Do not seek out or attempt to use these engineered probiotics, as they are not commercially available and their safety in humans is unknown. If you have questions about probiotic safety or are considering probiotic supplements for health reasons, consult with your healthcare provider. This article is for educational purposes only and should not be considered medical advice.