A new probiotic bacteria called Levilactobacillus brevis M3R3, discovered in traditional Khiki cheese, survived 83% of intestinal fluid exposure and reduced harmful Staphylococcus aureus bacteria by 82.2% in laboratory tests. According to Gram Research analysis, the bacteria also demonstrated antioxidant activity and cholesterol-removal properties while showing no safety concerns, making it a promising candidate for future probiotic development, though human studies are still needed.
Scientists discovered a new type of beneficial bacteria called Levilactobacillus brevis M3R3 in traditional Khiki cheese that could work as a probiotic supplement. According to Gram Research analysis, this bacteria survived stomach acid better than many probiotics, stayed alive in the digestive system, and showed strong ability to fight dangerous bacteria like Staphylococcus aureus. The research also found it had antioxidant properties and could help remove cholesterol. Safety tests showed no harmful effects, making it a promising candidate for future probiotic products that could support digestive and immune health.
Key Statistics
A 2026 laboratory study of Levilactobacillus brevis M3R3 found that the bacteria survived 83.0% of simulated intestinal fluid exposure and 67.8% of simulated gastric fluid exposure, suggesting strong potential to reach the intestines alive.
Research published in Antonie van Leeuwenhoek in 2026 showed that Levilactobacillus brevis M3R3 reduced Staphylococcus aureus biofilm formation to 17.8% and downregulated virulence genes icaA and hla by 83.2% and 58.4% respectively.
A 2026 analysis of Levilactobacillus brevis M3R3 demonstrated antioxidant activity with DPPH radical-scavenging of 54.05% and ABTS radical-scavenging of 62.75%, plus 39.0% cholesterol removal in the presence of bile.
Laboratory testing of Levilactobacillus brevis M3R3 in 2026 showed 78.2% auto-aggregation ability and demonstrated no hemolysis, DNase activity, biogenic amine production, or β-glucuronidase activity, supporting its safety profile as a probiotic candidate.
The Quick Take
- What they studied: Whether a newly discovered bacteria from traditional cheese could work as a safe and effective probiotic to support digestive health and fight harmful bacteria
- Who participated: Laboratory testing of a bacterial strain isolated from Khiki cheese, using cell cultures and simulated digestive conditions to evaluate safety and effectiveness
- Key finding: The bacteria survived 67.8% of stomach acid exposure and 83% of intestinal fluid exposure, while also reducing harmful Staphylococcus aureus bacteria by 82.2% and showing antioxidant activity of 54-63%
- What it means for you: This bacteria may eventually be developed into a probiotic supplement to support digestive health and immunity, though human testing is still needed before it becomes available as a consumer product
The Research Details
Scientists isolated a new strain of bacteria from traditional Khiki cheese and tested it in laboratory conditions to see if it had probiotic properties. They identified the bacteria using multiple testing methods including genetic analysis and biochemical profiles. The researchers then exposed the bacteria to conditions mimicking the human digestive system—including stomach acid at pH 2.5 and simulated intestinal fluids—to see if it could survive the journey through the digestive tract.
They also tested whether the bacteria could stick to intestinal cells, fight harmful bacteria, and remove cholesterol. Finally, they ran safety tests to make sure the bacteria didn’t produce toxins or cause damage to human cells. This comprehensive approach allowed them to evaluate whether this bacteria had all the characteristics needed to be a good probiotic candidate.
This research approach is important because it uses realistic laboratory conditions that mimic what actually happens in the human body. By testing survival in stomach acid and intestinal fluids, scientists can predict whether a probiotic will actually reach the intestines alive—which is essential for it to work. Testing against harmful bacteria and checking for safety markers ensures the bacteria won’t cause problems while providing benefits.
The study used multiple standardized testing methods to identify and evaluate the bacteria, which increases reliability. The researchers tested survival rates with specific percentages and measured gene expression changes, showing precise scientific measurement. However, this is laboratory research only—human studies would be needed to confirm these benefits work in real people. The study doesn’t specify how many samples were tested, which is a limitation.
What the Results Show
The bacteria demonstrated impressive survival abilities in harsh digestive conditions. When exposed to stomach acid at pH 2.5, it maintained viable counts of 4.847 log CFU/mL, meaning a significant portion remained alive. In simulated gastric fluid, 67.8% of the bacteria survived, and in simulated intestinal fluid, 83.0% survived. These survival rates are important because probiotics must reach the intestines alive to provide benefits.
The bacteria also showed strong ability to interact with intestinal cells. It demonstrated 78.2% hydrophobicity (ability to stick to surfaces), 78.2% auto-aggregation (ability to clump together), and 13.7% adhesion to Caco-2 cells, which are human intestinal cells used in research. This suggests the bacteria could attach to the intestinal lining and persist there temporarily.
Against harmful bacteria, the bacteria was remarkably effective. Its cell-free supernatant (the liquid produced by the bacteria) reduced Staphylococcus aureus biofilm formation to just 17.8% at 4 times the minimum inhibitory concentration. This was associated with downregulation of virulence genes icaA (reduced by 83.2%) and hla (reduced by 58.4%), meaning the bacteria essentially turned off the genes that make S. aureus dangerous.
The bacteria showed antioxidant properties, with DPPH radical-scavenging activity of 54.05% and ABTS radical-scavenging activity of 62.75%. These measurements indicate the bacteria can neutralize harmful free radicals in the body. Additionally, the bacteria removed 39.0% of cholesterol in the presence of bile, suggesting potential cardiovascular benefits. Safety testing revealed no hemolysis (damage to red blood cells), no DNase activity (which could damage DNA), no biogenic amine production (which can cause adverse reactions), and no β-glucuronidase activity (which could reactivate harmful compounds). These negative results are actually positive findings that support the bacteria’s safety profile.
This research builds on existing knowledge that fermented foods like cheese contain beneficial bacteria with probiotic potential. The survival rates observed in this study (67.8% in gastric fluid, 83.0% in intestinal fluid) are comparable to or better than many commercial probiotic strains currently available. The bacteria’s ability to fight Staphylococcus aureus and produce antioxidants aligns with known benefits of other lactic acid bacteria, but the specific genetic mechanisms identified here (icaA and hla gene downregulation) provide new insights into how this particular strain works.
This study was conducted entirely in laboratory conditions using cell cultures and simulated digestive fluids—not in actual human bodies. The results cannot be directly applied to humans without clinical trials. The study doesn’t specify the exact number of bacterial samples tested or provide detailed statistical analysis. Additionally, the adhesion rate to intestinal cells (13.7%) was relatively modest, which may limit how well the bacteria persists in the gut. The study also doesn’t evaluate how the bacteria performs when combined with other probiotics or how it survives in actual food products over time.
The Bottom Line
Based on this laboratory research, Levilactobacillus brevis M3R3 shows promise as a future probiotic supplement with moderate to strong evidence for safety and potential benefits. However, human clinical trials are necessary before making any health claims or recommendations. If this bacteria is eventually developed into a commercial product, it should be used as directed and may be most beneficial for people interested in supporting digestive health and immunity. Confidence level: Moderate for laboratory findings; Low for real-world human application until clinical trials are completed.
This research is most relevant to probiotic manufacturers, gastroenterologists, and people interested in functional foods and digestive health. People with compromised immune systems, severe digestive disorders, or those taking immunosuppressive medications should consult healthcare providers before using any new probiotic. This research is not yet applicable to general consumers since the bacteria is not commercially available.
Laboratory studies like this typically take 2-5 years before advancing to animal studies, and another 3-7 years for human clinical trials. If development proceeds smoothly, a commercial product might be available in 5-10 years. Any health benefits would likely appear gradually over weeks to months of consistent use, not immediately.
Frequently Asked Questions
What is Levilactobacillus brevis M3R3 and where does it come from?
It’s a beneficial bacteria discovered in traditional Khiki cheese that shows probiotic potential. Scientists identified it through laboratory testing and found it survived stomach acid better than many probiotics while fighting harmful bacteria like Staphylococcus aureus.
Can this bacteria survive stomach acid and reach my intestines?
Laboratory tests show yes—83% survived simulated intestinal fluid and 67.8% survived simulated stomach acid. However, these are lab conditions; actual human digestion may differ. Human studies are needed to confirm real-world effectiveness.
Is Levilactobacillus brevis M3R3 safe to consume as a probiotic?
Laboratory safety tests showed no harmful effects—no toxin production, no damage to cells, and no dangerous compounds. However, this is preliminary research. Full human safety studies are required before it becomes available as a consumer product.
When will this probiotic be available to buy?
This is early-stage laboratory research. Commercial availability typically requires 5-10 years of additional development, animal studies, and human clinical trials. It’s not currently available for purchase.
What health benefits could this bacteria provide?
Laboratory findings suggest potential benefits including fighting harmful bacteria, antioxidant activity (54-63% free radical scavenging), and cholesterol removal (39%). However, human studies are needed to confirm these benefits actually work in people.
Want to Apply This Research?
- Once this probiotic becomes available, users could track daily consumption and monitor digestive symptoms (bloating, regularity, energy levels) using a simple 1-5 scale rating system, with weekly summaries to identify patterns
- Set a daily reminder to take the probiotic at the same time each day (ideally with food), and log it in the app to build consistency and track adherence to the supplement routine
- Create a 12-week tracking period to monitor changes in digestive comfort, energy levels, and immune health markers (like frequency of colds), comparing baseline measurements to weekly and monthly progress
This research describes laboratory findings only and has not been tested in humans. Levilactobacillus brevis M3R3 is not currently available as a commercial product. These findings should not be interpreted as health claims or recommendations for treatment. Anyone considering probiotic supplements should consult with a healthcare provider, especially those with compromised immune systems, severe digestive disorders, or those taking medications. This article is for educational purposes and does not replace professional medical advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.