A specific probiotic bacteria called Lactobacillus johnsonii DM2420 reduced bad cholesterol and increased good cholesterol in mice eating a high-fat diet, while also improving the balance of gut bacteria. According to Gram Research analysis, the bacteria worked by reducing fat storage genes and changing which microbes lived in the intestines, suggesting it could become a natural treatment for high cholesterol—though human studies are still needed to confirm these effects work in people.
Researchers studied a specific probiotic bacteria called Lactobacillus johnsonii DM2420 to see if it could help people with high cholesterol and unhealthy fat levels in their blood. Using mice fed a high-fat diet, scientists found that this probiotic reduced harmful cholesterol, increased good cholesterol, and changed the balance of bacteria in the gut. The bacteria appeared to work by turning off genes that tell the body to store more fat. According to Gram Research analysis, these findings suggest this probiotic could become a natural treatment option for people struggling with lipid metabolism disorders, though human studies are still needed.
Key Statistics
In a 2026 research study, Lactobacillus johnsonii DM2420 reduced total cholesterol and LDL (bad cholesterol) while increasing HDL (good cholesterol) in mice fed a high-fat diet, demonstrating the probiotic’s potential to improve lipid metabolism.
A 2026 study found that Lactobacillus johnsonii DM2420 increased beneficial gut bacteria including Adlercreutzia and Bifidobacterium while reducing Allobaculum, a bacteria identified as central to the development of high cholesterol in mice.
Research published in 2026 showed that Lactobacillus johnsonii DM2420 reduced the expression of CD36 and SREBP1 genes in mice, which are responsible for telling the body to store fat, suggesting the probiotic works by making fat storage less efficient.
The Quick Take
- What they studied: Whether a specific probiotic bacteria (Lactobacillus johnsonii DM2420) could lower cholesterol and improve gut bacteria balance in mice eating a high-fat diet.
- Who participated: Laboratory mice that were fed a high-fat diet to mimic human cholesterol problems. Researchers also tested the bacteria on fat cells grown in dishes.
- Key finding: The probiotic bacteria reduced bad cholesterol (LDL) and total cholesterol while increasing good cholesterol (HDL) in mice. It also changed which bacteria lived in the gut and reduced fat storage in the liver.
- What it means for you: This research suggests a probiotic supplement might help manage high cholesterol naturally, but these are early-stage findings from animal studies. Human trials are needed before doctors could recommend it as a treatment.
The Research Details
Scientists conducted two types of experiments. First, they tested the probiotic bacteria on fat cells in laboratory dishes to see if it could stop fat from building up. Second, they gave the probiotic to mice eating a high-fat diet and measured changes in their blood cholesterol, liver fat, and gut bacteria over time. They compared mice that received the probiotic to mice that didn’t receive it to see what differences appeared.
The researchers measured several important markers: total cholesterol, LDL (bad cholesterol), HDL (good cholesterol), triglycerides (another type of fat), and free fatty acids. They also analyzed the genetic activity in fat cells and identified which bacteria were living in the mice’s intestines before and after treatment.
This approach allowed scientists to understand not just whether the probiotic worked, but also how it worked by looking at changes in genes and bacteria composition.
Testing in animals first is important because it allows researchers to control all variables and measure internal changes (like liver fat and gene expression) that would be difficult to study in humans. This research design helps establish whether a treatment is safe and effective before moving to human trials. Understanding the mechanism—how the probiotic actually works—is crucial for developing better treatments.
This is laboratory research published in a peer-reviewed scientific journal, which means other experts reviewed it before publication. However, the findings are from animal studies, not humans, so results may not directly translate. The study appears well-designed with clear measurements and comparisons, but the sample size for mice wasn’t specified in the abstract. Human clinical trials would be needed to confirm these effects work in people.
What the Results Show
The probiotic bacteria significantly reduced harmful cholesterol levels in the blood of mice eating a high-fat diet. Specifically, it lowered total cholesterol, LDL cholesterol (the ‘bad’ kind), and free fatty acids while increasing HDL cholesterol (the ‘good’ kind). These changes suggest the bacteria helped the mice’s bodies handle fat more efficiently.
The probiotic also reduced fat buildup in the liver, which is important because fatty liver disease often accompanies high cholesterol. Additionally, the bacteria reduced cholesterol and triglycerides in the mice’s feces, indicating the body was eliminating excess fat rather than storing it.
At the cellular level, the probiotic reduced the activity of genes that tell fat cells to store more fat and reduced a protein called CD36 that helps cells absorb fatty acids. This suggests the bacteria works by making the body less efficient at storing excess fat.
The probiotic changed the composition of bacteria living in the mice’s intestines. It increased beneficial bacteria called Adlercreutzia and Bifidobacterium while decreasing a bacteria called Allobaculum. The researchers found that Allobaculum was a central hub in the gut bacteria network, suggesting it plays an important role in developing high cholesterol. By reducing this bacteria, the probiotic may have helped restore healthy fat metabolism.
This study builds on the researchers’ earlier work showing this same probiotic had anti-inflammatory effects and could modify gut bacteria. This new research goes deeper by examining how the bacteria specifically affects cholesterol and fat metabolism. The findings align with growing scientific understanding that gut bacteria composition significantly influences how the body processes fats and cholesterol.
This research was conducted in mice, not humans, so results may not directly apply to people. The study didn’t specify how many mice were used or provide detailed statistical analysis in the abstract. The high-fat diet in mice may not perfectly mimic human diet and lifestyle. Additionally, the study doesn’t tell us the optimal dose for humans, how long treatment would need to continue, or whether the effects would persist long-term. Human clinical trials are essential before this probiotic could be recommended as a medical treatment.
The Bottom Line
Based on this research, Lactobacillus johnsonii DM2420 shows promise as a potential probiotic treatment for high cholesterol and lipid metabolism disorders. However, confidence in this recommendation is currently low because the evidence comes only from animal studies. Before using this specific probiotic as a treatment, people should wait for human clinical trials. In the meantime, established approaches like diet changes, exercise, and prescribed medications remain the evidence-based options for managing cholesterol.
People with high cholesterol, fatty liver disease, or metabolic disorders should find this research interesting, as it suggests a natural approach might help. However, this research is too early-stage for anyone to change their treatment based on it. People currently taking cholesterol medications should not stop or change their treatment without consulting their doctor. Researchers studying probiotics and metabolic health should also pay attention to these findings.
In the mice studied, changes in cholesterol levels appeared within the timeframe of the experiment, but the abstract doesn’t specify exactly how long this took. If this probiotic eventually reaches human trials and proves effective, it would likely take weeks to months to see meaningful changes in cholesterol levels, similar to how other probiotic interventions work. Long-term studies would be needed to determine if benefits persist with continued use.
Frequently Asked Questions
Can this probiotic bacteria help lower my cholesterol?
Lactobacillus johnsonii DM2420 reduced cholesterol in mice studies, but human trials haven’t been conducted yet. Current evidence-based treatments for high cholesterol include diet changes, exercise, and medications prescribed by your doctor. Consult your healthcare provider before trying new supplements.
How does this probiotic work to reduce cholesterol?
The bacteria appears to work by reducing the activity of genes that tell fat cells to store fat and by changing which bacteria live in your gut. It increases beneficial bacteria like Bifidobacterium while reducing Allobaculum, a bacteria linked to cholesterol problems in animal studies.
When will this probiotic be available as a treatment?
This research is still in early stages with only animal studies completed. Human clinical trials would need to happen first to test safety and effectiveness in people. This typically takes several years, so availability as a medical treatment is likely years away.
Is this probiotic safe to use right now?
The research doesn’t provide safety data for humans. While Lactobacillus bacteria are generally considered safe, this specific strain hasn’t been tested in human clinical trials. Always consult your doctor before starting any new supplement, especially if you take medications or have health conditions.
What should I do about my high cholesterol while waiting for this research?
Work with your doctor on proven strategies: eat less saturated fat, exercise regularly, maintain a healthy weight, and take prescribed medications if recommended. These approaches have strong evidence for reducing cholesterol and heart disease risk. Discuss any supplements with your healthcare provider first.
Want to Apply This Research?
- Users interested in cholesterol management could track their lipid panel results (total cholesterol, LDL, HDL, triglycerides) every 3 months if they’re using probiotics, noting the specific strain and dosage used alongside dietary changes and exercise.
- Once this probiotic becomes available for human use, users could set a daily reminder to take the supplement at the same time each day, paired with logging their meals to track whether dietary changes combined with the probiotic show benefits in their next cholesterol test.
- Create a quarterly check-in to review lipid panel results and correlate them with probiotic use, diet quality, and exercise frequency. Track any digestive changes or side effects. Compare results over 6-12 months to identify trends, noting that meaningful changes in cholesterol typically require sustained effort over months.
This research is from animal studies and has not been tested in humans. The findings are preliminary and should not be used to guide personal medical decisions. If you have high cholesterol or a lipid metabolism disorder, consult your healthcare provider about evidence-based treatments including diet, exercise, and medications. Do not stop, start, or change any cholesterol medications without medical supervision. This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.