Researchers discovered a new type of helpful bacteria called MacFasB02 that might help people with high cholesterol. The bacteria was found in monkeys that stayed healthy even when eating lots of fatty foods. When scientists gave this bacteria to mice on a high-fat diet for 13 weeks, the mice gained less weight, had lower cholesterol levels, and showed less inflammation in their bodies. The bacteria appears to work by producing a natural chemical called adenosine that helps the body manage cholesterol better. This discovery could lead to a new natural treatment for high cholesterol that might be safer than current medications.

The Quick Take

  • What they studied: Whether a newly discovered probiotic bacteria (MacFasB02) could help reduce high cholesterol and inflammation in the body
  • Who participated: Laboratory studies using mice fed a high-fat diet for 13 weeks, plus laboratory tests with human liver cells. The bacteria was originally isolated from monkeys that naturally stayed healthy on high-fat diets
  • Key finding: Mice that received MacFasB02 bacteria showed significant reductions in triglycerides (blood fats), LDL cholesterol (bad cholesterol), and total cholesterol, plus less liver damage and inflammation compared to mice that didn’t receive the bacteria
  • What it means for you: This research suggests a potential new probiotic treatment for high cholesterol that works through a natural mechanism. However, this is early-stage research in animals and lab settings—human studies are needed before this could become a treatment option

The Research Details

Scientists took a multi-step approach to understand how this bacteria works. First, they isolated MacFasB02 from monkey fecal samples and tested whether it could survive in acidic stomach conditions and bile. Then they fed this bacteria to mice eating a high-fat diet for 13 weeks and measured changes in weight, cholesterol levels, liver health, and gut bacteria composition. They also used advanced laboratory techniques to identify which specific compounds the bacteria produces and how those compounds affect liver cells in a dish. Finally, they used genetic analysis to understand the exact mechanisms involved in cholesterol management.

This comprehensive approach is important because it doesn’t just show that the bacteria works—it explains how and why it works. By identifying adenosine as the key active compound, researchers can better understand whether this bacteria could be developed into a safe treatment. Testing in multiple ways (living mice, liver cells, genetic analysis) makes the findings more reliable than a single type of experiment

Strengths: The study used multiple complementary research methods (animal studies, cell studies, genetic analysis, and metabolite identification) which strengthens confidence in the findings. The bacteria was isolated from a real-world source (monkeys adapted to high-fat diets). Limitations: This is preliminary research conducted only in animals and laboratory cells—human studies haven’t been done yet. The exact sample sizes for mouse experiments aren’t clearly specified. Results in mice don’t always translate to humans. The study was published in 2026, so long-term safety data in humans is unavailable

What the Results Show

Mice receiving MacFasB02 bacteria showed impressive improvements across multiple measures. After 13 weeks, these mice gained significantly less weight compared to control mice. Their blood triglyceride levels (a type of fat) dropped substantially, and their LDL cholesterol (often called ‘bad cholesterol’) and total cholesterol both decreased. The bacteria also protected the liver—mice showed less fatty liver disease and less inflammation throughout their bodies. When researchers examined the intestines under a microscope, they found that the bacteria helped restore the gut lining’s protective barrier by improving the structure of intestinal projections (villi) and increasing protective mucus-producing cells. The gut bacteria composition also shifted in beneficial ways, suggesting the MacFasB02 bacteria changed the overall microbial community in positive directions.

Advanced genetic testing revealed that the bacteria activated genes involved in cholesterol transport and management, specifically genes called Apoa1 and Pltp. Laboratory tests with human liver cells showed that adenosine—a natural chemical produced by the bacteria—reduced fat accumulation and inflammation in the cells by triggering these same cholesterol-management genes. This suggests the bacteria’s benefits come from a specific, identifiable mechanism rather than random effects

High cholesterol is typically treated with prescription medications like statins, which can have side effects in some people. This research builds on growing evidence that certain probiotics can influence cholesterol levels, but MacFasB02 appears unique because it was isolated from animals naturally resistant to high-fat diets. Previous probiotic studies have shown mixed results; this study’s identification of adenosine as the active mechanism is a novel contribution that could help explain why some probiotics work better than others

This research has important limitations to consider: All experiments were conducted in mice or laboratory cells—human studies are essential before any health claims can be made. The study doesn’t specify exact numbers of mice used in each experiment. We don’t know if the benefits would persist beyond 13 weeks or what the long-term safety profile might be. The bacteria was tested only in mice eating a high-fat diet; we don’t know if it would help people with normal diets. No comparison was made to standard cholesterol medications. The study doesn’t address whether the bacteria would survive the journey through the human digestive system or colonize the human gut effectively

The Bottom Line

Based on current evidence (LOW confidence for human application): This research is too preliminary to recommend MacFasB02 as a treatment. It shows promise in animal models and warrants human clinical trials. If you have high cholesterol, continue following your doctor’s current treatment plan. Do not replace prescribed medications with untested probiotics. If human studies eventually confirm safety and effectiveness, MacFasB02 might become a complementary option, but this is years away from reality

This research is most relevant to: People with high cholesterol seeking alternative or complementary approaches; Researchers developing probiotic treatments; Pharmaceutical companies interested in live biotherapeutics; People interested in how gut bacteria influence metabolism. This research is NOT a treatment recommendation for anyone currently managing high cholesterol

In the mouse studies, benefits appeared over 13 weeks. If human trials eventually occur and succeed, it typically takes 5-10 years for a new probiotic treatment to reach the market. Even then, benefits might take weeks to months to appear, and individual results would likely vary

Want to Apply This Research?

  • If this treatment becomes available in the future, users could track: Weekly weight measurements, monthly cholesterol levels (if testing at home or clinic), daily digestive symptoms (bloating, regularity), and energy levels. This would help identify whether the probiotic is working for their individual situation
  • Users could combine any future MacFasB02 treatment with: Reducing high-fat food intake, increasing fiber from vegetables and whole grains, tracking daily steps or exercise, and maintaining consistent meal timing. The app could remind users to take the probiotic at the same time daily and log dietary choices to identify patterns
  • Long-term tracking would involve: Monthly weight trends, quarterly cholesterol checks (coordinated with healthcare provider), ongoing digestive health notes, and periodic assessment of inflammation markers (energy levels, joint comfort, general wellness). Users should maintain regular doctor visits to compare app-tracked data with clinical measurements

This research describes early-stage laboratory and animal studies of a novel probiotic bacteria. MacFasB02 is not currently available as a treatment, and human safety and effectiveness have not been established. This article is for educational purposes only and should not be interpreted as medical advice or a treatment recommendation. If you have high cholesterol or related health concerns, consult with your healthcare provider before making any changes to your treatment plan. Do not discontinue prescribed medications based on this research. Always discuss any interest in probiotic supplements with your doctor, as they may interact with medications or underlying health conditions.