Scientists discovered that a special type of bacteria found in fermented tea produces a unique substance that could help people lose weight and lower their cholesterol. When researchers tested this substance in mice eating a high-fat diet, it worked better than some existing treatments at reducing bad cholesterol and preventing weight gain. The substance works by changing the types of bacteria in the gut, which then produce helpful chemicals that reduce fat buildup in the liver. This discovery suggests a new way to help people with weight and cholesterol problems, though more human studies are needed to confirm these benefits.

The Quick Take

  • What they studied: Whether a special substance produced by bacteria from fermented tea could help reduce weight gain, lower cholesterol, and improve liver health in mice eating unhealthy high-fat diets
  • Who participated: Laboratory mice that were fed high-fat diets to mimic obesity and high cholesterol in humans. The study compared different doses of the bacterial substance against standard treatments
  • Key finding: Even small amounts of the bacterial substance (50 mg per kilogram of body weight) significantly lowered bad cholesterol better than comparison treatments, while larger amounts reduced weight gain as effectively as existing cholesterol-lowering supplements
  • What it means for you: This research suggests a potential new natural treatment for weight gain and high cholesterol, but it’s important to note these are early-stage animal studies. Human trials would be needed before this could become a real treatment option

The Research Details

Researchers isolated a special bacteria called Bacillus amyloliquefaciens D189 from fermented Liu-pao tea. This bacteria produces a unique substance made of sugar chains (called an exopolysaccharide). The scientists first analyzed exactly what this substance was made of and how it was structured—discovering it had a never-before-seen arrangement in this type of bacteria.

They then tested this substance in laboratory mice that were eating high-fat diets to make them overweight and develop high cholesterol, similar to obesity in humans. Different groups of mice received different amounts of the bacterial substance, while control groups received either no treatment or existing cholesterol-lowering supplements. The researchers measured changes in weight, cholesterol levels, liver fat, and the types of bacteria living in the mice’s guts.

The study also examined the chemical pathways and signals that the bacterial substance activated in the body, particularly focusing on how it changed gut bacteria and affected liver function.

This research approach is important because it traces the complete pathway from a natural source (fermented tea) through the discovery of a new substance, to understanding exactly how that substance works in the body. Rather than just showing that something works, the researchers explained the mechanism—how the bacterial substance changes gut bacteria, which then produce helpful chemicals that reduce fat in the liver. This detailed understanding is crucial for developing new treatments.

This is a well-designed laboratory study with careful analysis of the bacterial substance’s structure and multiple measurements of its effects. The researchers compared their results against positive control treatments (existing supplements), which strengthens the findings. However, this is animal research in mice, not human studies, so results may not directly apply to people. The study was published in a peer-reviewed scientific journal, indicating it met quality standards for publication. The specific bacterial substance tested is unique and newly characterized, which is scientifically significant.

What the Results Show

The bacterial substance showed impressive results at very low doses. When mice received just 50 mg per kilogram of body weight, their bad cholesterol (LDL-C) dropped more than it did in mice receiving standard cholesterol-lowering supplements. This is significant because it suggests the bacterial substance might be more potent than existing treatments.

At higher doses (200 mg per kilogram), the bacterial substance reduced weight gain in the mice just as effectively as 300 mg per kilogram of a standard supplement called inulin-type polysaccharides. This means the bacterial substance appeared to work better per unit of dose—you needed less of it to get similar results.

The researchers discovered that the bacterial substance worked by changing which bacteria lived in the mice’s guts. It increased helpful bacteria that produce butyrate and other short-chain fatty acids (chemicals that are good for health), while reducing bacteria that cause inflammation. The amount of butyrate increased by nearly 63%, and another beneficial chemical called isovalerate increased by about 74%.

Beyond weight and cholesterol, the treatment improved liver health by reducing fat buildup in liver cells. The bacterial substance also changed how the body processes bile acids (digestive chemicals), shifting the balance toward secondary bile acids, which are associated with better metabolic health. The treatment restored normal signaling in the liver through a pathway called FXR signaling, which is important for controlling fat metabolism. Additionally, the treatment improved how well the intestines absorb and transport bile acids, suggesting improved gut-liver communication.

This research builds on the researchers’ earlier discovery that this same bacteria had cholesterol-lowering properties. The new study goes much deeper by revealing the exact structure of the bacterial substance and explaining how it works. The unique sugar-chain structure they discovered has never been found before in this type of bacteria, making it scientifically novel. The findings align with what scientists know about how gut bacteria influence weight and cholesterol, but this particular bacterial substance appears to be more effective at lower doses than some existing treatments.

The most important limitation is that this research was conducted in mice, not humans. Mouse studies don’t always translate directly to human health—what works in mice may not work the same way in people. The study didn’t specify exactly how many mice were used in each group. The research was conducted in laboratory conditions with controlled diets, which is very different from real-world eating patterns. The study focused on mice with diet-induced obesity, so results may not apply to people with obesity from other causes. Additionally, this is a single study from one research group, so the findings would need to be confirmed by other independent researchers before being considered definitive.

The Bottom Line

Based on this research, there is promising but preliminary evidence that this bacterial substance could help with weight management and cholesterol control. However, these are early-stage findings from animal studies. Current recommendation level: This is not yet ready for human use. Further research, including human clinical trials, would be needed before this could become a medical treatment. If you’re interested in natural approaches to cholesterol and weight management, discuss evidence-based options with your doctor.

This research is most relevant to people interested in natural treatments for obesity and high cholesterol, as well as researchers studying gut bacteria and metabolism. Scientists studying fermented foods and their health benefits should find this particularly interesting. People with metabolic disorders, obesity, or high cholesterol may eventually benefit if this research leads to human treatments, but that’s not yet the case. This research is NOT a recommendation for people to seek out fermented tea or similar products as a treatment—the specific bacterial substance tested is not yet available as a consumer product.

In the mice studied, the beneficial effects on cholesterol appeared relatively quickly, but the weight loss effects took longer to develop. If this were eventually tested in humans, realistic timelines would likely be weeks to months to see meaningful changes in cholesterol and weight. However, this is speculative since human studies haven’t been conducted yet.

Want to Apply This Research?

  • Once human treatments become available (if they do), users could track weekly cholesterol levels (if they have access to testing) and weekly weight measurements to monitor the treatment’s effectiveness over 8-12 weeks
  • Currently, users interested in this research could use the app to track their consumption of fermented foods (like fermented tea, kombucha, or other fermented beverages) and correlate these with their weight and cholesterol markers, while waiting for more definitive human research
  • Establish a baseline measurement of weight and cholesterol (through blood tests), then track these metrics monthly while maintaining consistent diet and exercise habits. This would help users see if any dietary changes correlate with improvements, though individual results will vary significantly

This research describes laboratory studies in mice and has not been tested in humans. The bacterial substance discussed is not currently available as a consumer product or medical treatment. These findings are preliminary and should not be used to guide personal health decisions. Anyone with high cholesterol, obesity, or metabolic disorders should consult with their healthcare provider about evidence-based treatment options. This article is for educational purposes only and does not constitute medical advice. Do not attempt to self-treat based on this research.